diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..6008471
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,16 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "commons"
+version = "0.1.0"
+description = "small stdlib-only sync helpers: time/timezone deltas, dotted-path dict access, display masking, and ip/address tooling"
+requires-python = ">=3.10"
+dependencies = []
+
+[project.optional-dependencies]
+addr = ["aiohttp>=3.9"]
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/commons"]
diff --git a/src/commons/__init__.py b/src/commons/__init__.py
new file mode 100644
index 0000000..a95cd90
--- /dev/null
+++ b/src/commons/__init__.py
@@ -0,0 +1,61 @@
+"""commons — small sync helpers shared across projects.
+
+timing:  unix-timestamp deltas + timezone-aware datetime conversions, bare
+         functions and a configurable Clock.
+paths:   nested dict/list access by dotted path (deep_get / deep_set).
+masking: display masking for cards / cvv / tokens (cosmetic, not a security control).
+addr:    ip/address tooling — pure stdlib ip utils (`commons.addr.ip`) in base,
+         async geo lookups (`commons.addr.geo`) behind the `commons[addr]` extra.
+
+base is stdlib only, no dependencies (the addr geo lookups add aiohttp via the
+extra). to toggle the timing test mode for bare calls, set it on the module —
+`from commons import timing; timing.FAST_MODE = True` — or use `Clock(fast=True)`
+for instance-scoped control. addr is exposed as a submodule (`from commons import
+addr`); its ip helpers live under `commons.addr.ip` to keep top-level uncluttered.
+"""
+from . import addr, masking, paths, timing
+from .masking import credit, cvv, phantom, provider
+from .paths import deep_get, deep_set
+from .timing import (
+    UTC,
+    Clock,
+    add,
+    ago,
+    ahead,
+    convert,
+    date,
+    fmt,
+    is_expired,
+    now,
+    now_dt,
+    to_dt,
+    to_unix,
+)
+
+__all__ = [
+    "timing",
+    "paths",
+    "masking",
+    "addr",
+    "now",
+    "add",
+    "ahead",
+    "ago",
+    "is_expired",
+    "to_dt",
+    "to_unix",
+    "now_dt",
+    "convert",
+    "fmt",
+    "date",
+    "UTC",
+    "Clock",
+    "deep_get",
+    "deep_set",
+    "credit",
+    "cvv",
+    "phantom",
+    "provider",
+]
+
+__version__ = "0.1.0"
diff --git a/src/commons/addr/__init__.py b/src/commons/addr/__init__.py
new file mode 100644
index 0000000..f61ef80
--- /dev/null
+++ b/src/commons/addr/__init__.py
@@ -0,0 +1,55 @@
+"""addr — ip/address tooling for commons.
+
+two concerns:
+- `ip` — pure stdlib ipaddress utilities (validation, membership, cidr shape,
+  conversions). ships in the base install, no dependencies.
+- `geo` — async network lookups (public ip, ip->geo, reverse geocode). needs
+  aiohttp, gated behind the `commons[addr]` extra; importing this package is fine
+  without it, but calling a geo function raises until it is installed.
+
+the geo.ipify api_key is always injected by the caller — nothing is hardcoded.
+"""
+from . import geo, ip
+from .geo import fetch_ip, fetch_location, ip_location
+from .ip import (
+    broadcast_address,
+    from_int,
+    host_bits,
+    hosts,
+    in_any,
+    in_network,
+    is_global,
+    is_private,
+    is_valid,
+    netmask,
+    network_address,
+    num_addresses,
+    prefix_bits,
+    set_bits,
+    to_int,
+    version,
+)
+
+__all__ = [
+    "ip",
+    "geo",
+    "is_valid",
+    "version",
+    "to_int",
+    "from_int",
+    "is_private",
+    "is_global",
+    "in_network",
+    "in_any",
+    "network_address",
+    "broadcast_address",
+    "netmask",
+    "prefix_bits",
+    "host_bits",
+    "num_addresses",
+    "set_bits",
+    "hosts",
+    "fetch_ip",
+    "ip_location",
+    "fetch_location",
+]
diff --git a/src/commons/addr/geo.py b/src/commons/addr/geo.py
new file mode 100644
index 0000000..4755a9e
--- /dev/null
+++ b/src/commons/addr/geo.py
@@ -0,0 +1,133 @@
+"""async ip/geo network lookups (aiohttp, gated behind the [addr] extra).
+
+importing this module without aiohttp is fine; only calling a lookup without it
+raises a clear RuntimeError. each call may reuse a caller-supplied aiohttp
+ClientSession (`session=`) or create and close one internally.
+
+url-building and json->dict parsing are pulled into pure helpers (`_*_url`,
+`_parse_*`) so they unit-test without network. every lookup returns None on any
+request/parse failure (logged, never raised, never printed).
+
+security: the only secret is geo.ipify's `api_key`, which is a REQUIRED keyword on
+`ip_location` — the caller injects it. nothing is hardcoded here.
+"""
+import logging
+from typing import Optional
+from urllib.parse import urlencode
+
+log = logging.getLogger(__name__)
+
+try:
+    import aiohttp
+
+    _HAVE_AIOHTTP = True
+except ImportError:  # pragma: no cover
+    aiohttp = None  # type: ignore[assignment]
+    _HAVE_AIOHTTP = False
+
+_MISSING = "aiohttp is required for address lookups; install commons[addr]"
+
+_IPIFY_URL = "https://api.ipify.org?format=json"
+_GEO_IPIFY_URL = "https://geo.ipify.org/api/v2/country"
+_NOMINATIM_URL = "https://nominatim.openstreetmap.org/reverse"
+
+
+def _ip_location_url(ip: str, api_key: str) -> str:
+    """build the geo.ipify lookup url for an ip (api_key injected by the caller)"""
+    return f"{_GEO_IPIFY_URL}?{urlencode({'apiKey': api_key, 'ipAddress': ip})}"
+
+
+def _reverse_url(lat: float, lon: float) -> str:
+    """build the nominatim reverse-geocode url for a lat/lon"""
+    params = {
+        "format": "json",
+        "lat": lat,
+        "lon": lon,
+        "zoom": 5,
+        "addressdetails": 1,
+    }
+    return f"{_NOMINATIM_URL}?{urlencode(params)}"
+
+
+def _parse_ipify(data: dict) -> Optional[str]:
+    """pull the ip string out of an ipify response"""
+    ip = data.get("ip")
+    return ip or None
+
+
+def _parse_reverse(data: dict) -> Optional[dict]:
+    """parse a nominatim reverse response into {country: iso2 lower, state: slug|None}"""
+    address = data.get("address")
+    if not isinstance(address, dict):
+        return None
+    country = address.get("country_code")
+    if not country:
+        return None
+    state = address.get("state")
+    return {
+        "country": str(country).lower(),
+        "state": state.lower().replace(" ", "-") if state else None,
+    }
+
+
+async def _get_json(
+    url: str, *, session, timeout: float, headers: Optional[dict] = None
+) -> Optional[dict]:
+    """GET url and return parsed json, or None on any failure; reuses session if given"""
+    if not _HAVE_AIOHTTP:
+        raise RuntimeError(_MISSING)
+    owns = session is None
+    if owns:
+        session = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=timeout))
+    try:
+        async with session.get(url, headers=headers) as resp:
+            if resp.status != 200:
+                log.warning("address lookup %s -> %s", url, resp.status)
+                return None
+            return await resp.json()
+    except Exception as exc:
+        log.warning("address lookup failed (%s): %s", url, exc)
+        return None
+    finally:
+        if owns:
+            await session.close()
+
+
+async def fetch_ip(*, session=None, timeout: float = 15) -> Optional[str]:
+    """return the caller's public ip via ipify, or None on failure"""
+    data = await _get_json(_IPIFY_URL, session=session, timeout=timeout)
+    return _parse_ipify(data) if data else None
+
+
+async def ip_location(
+    ip: str, *, api_key: str, session=None, timeout: float = 15
+) -> Optional[dict]:
+    """look up geo data for an ip via geo.ipify; api_key is required and injected
+
+    returns the raw geo.ipify json dict, or None on failure. raises ValueError if
+    no api_key is supplied — there is no default and nothing hardcoded.
+    """
+    if not api_key:
+        raise ValueError("ip_location requires an api_key (inject it; never hardcode)")
+    url = _ip_location_url(ip, api_key)
+    return await _get_json(url, session=session, timeout=timeout)
+
+
+async def fetch_location(
+    lat: float,
+    lon: float,
+    *,
+    user_agent: str = "commons-addr/1.0",
+    session=None,
+    timeout: float = 15,
+) -> Optional[dict]:
+    """reverse-geocode a lat/lon via nominatim -> {country, state}, or None
+
+    nominatim's terms require a User-Agent; it is a parameter (not hidden) with a
+    sensible default the caller can override.
+    """
+    url = _reverse_url(lat, lon)
+    data = await _get_json(
+        url, session=session, timeout=timeout, headers={"User-Agent": user_agent}
+    )
+    return _parse_reverse(data) if data else None
diff --git a/src/commons/addr/ip.py b/src/commons/addr/ip.py
new file mode 100644
index 0000000..4b5abfd
--- /dev/null
+++ b/src/commons/addr/ip.py
@@ -0,0 +1,123 @@
+"""pure ip/address utilities over stdlib ipaddress (no network, no deps).
+
+every function accepts strings. validation/membership helpers
+(`is_valid`/`version`/`in_network`/`in_any`) never raise on bad input — they return
+a falsy value. functions that require a valid address or cidr (`to_int`/`set_bits`/
+the network-shape helpers) let `ValueError` propagate so misuse is visible.
+
+cidr parsing uses `ip_network(cidr, strict=False)` throughout, so host bits set in
+the network string are tolerated (e.g. "10.0.0.5/24").
+"""
+import ipaddress
+from typing import List, Optional
+
+
+def is_valid(addr: str) -> bool:
+    """whether addr parses as an ipv4 or ipv6 address"""
+    try:
+        ipaddress.ip_address(addr)
+        return True
+    except ValueError:
+        return False
+
+
+def version(addr: str) -> Optional[int]:
+    """ip version (4 or 6) for addr, or None if it is not a valid address"""
+    try:
+        return ipaddress.ip_address(addr).version
+    except ValueError:
+        return None
+
+
+def to_int(addr: str) -> int:
+    """integer value of an ip address (raises ValueError on a bad address)"""
+    return int(ipaddress.ip_address(addr))
+
+
+def from_int(n: int, *, version: int = 4) -> str:
+    """ip address string for an integer (version 4 or 6)"""
+    if version == 4:
+        return str(ipaddress.IPv4Address(n))
+    if version == 6:
+        return str(ipaddress.IPv6Address(n))
+    raise ValueError("version must be 4 or 6")
+
+
+def is_private(addr: str) -> bool:
+    """whether addr is in private/reserved space (raises on a bad address)"""
+    return ipaddress.ip_address(addr).is_private
+
+
+def is_global(addr: str) -> bool:
+    """whether addr is a public, globally-routable address (raises on a bad address)"""
+    return ipaddress.ip_address(addr).is_global
+
+
+def in_network(addr: str, cidr: str) -> bool:
+    """whether addr falls inside a single cidr; False on any bad input"""
+    try:
+        return ipaddress.ip_address(addr) in ipaddress.ip_network(cidr, strict=False)
+    except ValueError:
+        return False
+
+
+def in_any(addr: str, cidrs: List[str]) -> bool:
+    """whether addr falls inside any of the cidrs (allow/blocklists); False on bad input"""
+    try:
+        ip = ipaddress.ip_address(addr)
+    except ValueError:
+        return False
+    for cidr in cidrs:
+        try:
+            if ip in ipaddress.ip_network(cidr, strict=False):
+                return True
+        except ValueError:
+            continue
+    return False
+
+
+def network_address(cidr: str) -> str:
+    """network address of a cidr (e.g. 10.0.0.0 for 10.0.0.5/24)"""
+    return str(ipaddress.ip_network(cidr, strict=False).network_address)
+
+
+def broadcast_address(cidr: str) -> str:
+    """broadcast address of a cidr"""
+    return str(ipaddress.ip_network(cidr, strict=False).broadcast_address)
+
+
+def netmask(cidr: str) -> str:
+    """netmask of a cidr (e.g. 255.255.255.0)"""
+    return str(ipaddress.ip_network(cidr, strict=False).netmask)
+
+
+def prefix_bits(cidr: str) -> int:
+    """prefix length of a cidr (the /N)"""
+    return ipaddress.ip_network(cidr, strict=False).prefixlen
+
+
+def host_bits(cidr: str) -> int:
+    """number of host bits in a cidr (max prefix minus prefix length)"""
+    net = ipaddress.ip_network(cidr, strict=False)
+    return net.max_prefixlen - net.prefixlen
+
+
+def num_addresses(cidr: str) -> int:
+    """total addresses in a cidr (network + hosts + broadcast)"""
+    return ipaddress.ip_network(cidr, strict=False).num_addresses
+
+
+def set_bits(addr: str) -> int:
+    """population count of an address's integer value (raises on a bad address)"""
+    return bin(int(ipaddress.ip_address(addr))).count("1")
+
+
+def hosts(cidr: str, *, limit: Optional[int] = None) -> List[str]:
+    """usable host addresses of a cidr as strings; limit caps how many are materialized"""
+    gen = ipaddress.ip_network(cidr, strict=False).hosts()
+    out: List[str] = []
+    for host in gen:
+        out.append(str(host))
+        if limit is not None and len(out) >= limit:
+            break
+    return out
diff --git a/src/commons/masking.py b/src/commons/masking.py
new file mode 100644
index 0000000..eefd824
--- /dev/null
+++ b/src/commons/masking.py
@@ -0,0 +1,53 @@
+"""display masking for sensitive-looking values.
+
+these are DISPLAY helpers only — they format a value for showing in a UI or log
+(e.g. "•••• •••• •••• 1234"). they are not a security control: the underlying
+value is unchanged and still needs proper handling (encryption at rest, etc.).
+"""
+
+
+def _digits(value: str) -> str:
+    """keep only the digit characters of a string"""
+    return "".join(c for c in value if c.isdigit())
+
+
+def credit(card_number: str) -> str:
+    """mask a card number to bullets plus the last four digits"""
+    last4 = _digits(card_number)[-4:]
+    return "•••• •••• •••• " + last4
+
+
+def cvv(value: str) -> str:
+    """mask a cvv to bullets of the same length"""
+    return "•" * len(value)
+
+
+def phantom(value: str) -> str:
+    """show a long token as first-six...last-four (e.g. a hash or id)"""
+    return f"{value[:6]}...{value[-4:]}"
+
+
+def provider(card_number: str) -> str:
+    """short card brand from the number's prefix, or UNKW if undetermined
+
+    a BIN-prefix heuristic for display/labeling — not authoritative validation.
+    tolerates spaces/dashes and short or non-numeric input (returns UNKW).
+    """
+    n = _digits(card_number)
+    if not n:
+        return "UNKW"
+    if n.startswith("4"):
+        return "VISA"
+    if n[:2] in {"51", "52", "53", "54", "55"} or (len(n) >= 4 and 2221 <= int(n[:4]) <= 2720):
+        return "MC"
+    if n[:2] in {"34", "37"}:
+        return "AMEX"
+    if n.startswith("62") or n.startswith("81"):
+        return "UPAY"
+    if n.startswith("6011") or n.startswith("65") or (len(n) >= 3 and 644 <= int(n[:3]) <= 649):
+        return "DISC"
+    if n.startswith("35"):
+        return "JCB"
+    if n.startswith(("30", "36", "38", "39")):
+        return "DNRS"
+    return "UNKW"
diff --git a/src/commons/paths.py b/src/commons/paths.py
new file mode 100644
index 0000000..ff0c612
--- /dev/null
+++ b/src/commons/paths.py
@@ -0,0 +1,50 @@
+"""nested access by dotted path.
+
+`deep_get(data, "in.this.old.notation")` walks dicts (and lists, when a segment is
+a number) and returns a default instead of raising on a missing/!wrong path.
+`deep_set` writes a nested value, creating intermediate dicts.
+"""
+from typing import Any
+
+_MISSING = object()
+
+
+def deep_get(data: Any, path: str, default: Any = None, *, sep: str = ".") -> Any:
+    """get a nested value by dotted path, returning default if absent
+
+    dict keys are matched by name; a numeric segment indexes a list/tuple
+    (e.g. "items.0.id"). any missing key, out-of-range index, or non-container
+    along the way yields `default` rather than raising.
+    """
+    cur = data
+    for seg in path.split(sep):
+        if isinstance(cur, dict):
+            cur = cur.get(seg, _MISSING)
+            if cur is _MISSING:
+                return default
+        elif isinstance(cur, (list, tuple)):
+            try:
+                cur = cur[int(seg)]
+            except (ValueError, IndexError):
+                return default
+        else:
+            return default
+    return cur
+
+
+def deep_set(data: dict, path: str, value: Any, *, sep: str = ".") -> dict:
+    """set a nested value by dotted path, creating intermediate dicts
+
+    returns the same top-level dict for chaining. overwrites any non-dict value
+    sitting where an intermediate dict is needed.
+    """
+    segments = path.split(sep)
+    cur = data
+    for seg in segments[:-1]:
+        nxt = cur.get(seg)
+        if not isinstance(nxt, dict):
+            nxt = {}
+            cur[seg] = nxt
+        cur = nxt
+    cur[segments[-1]] = value
+    return data
diff --git a/src/commons/timing.py b/src/commons/timing.py
new file mode 100644
index 0000000..fe486ed
--- /dev/null
+++ b/src/commons/timing.py
@@ -0,0 +1,169 @@
+"""time helpers built on unix timestamps with timezone-aware datetime support.
+
+one engine, two ergonomics:
+- bare module functions (now/add/ahead/ago/is_expired/to_dt/...) operate on unix
+  ints for quick, stateless use. all delta math routes through `_delta_seconds`.
+- `Clock` holds a timezone + fast flag and delegates to the same functions, so a
+  configured clock and the bare functions never diverge.
+
+unix ints stay the storable value; datetimes are produced on demand in whatever
+timezone you ask for (stdlib zoneinfo, no pytz).
+"""
+import time as _time
+from datetime import datetime, timezone
+from typing import Optional, Union
+from zoneinfo import ZoneInfo
+
+# default fast flag for bare module calls. when True, every unit (day/hour/minute)
+# counts as one second so time-based flows run fast in tests. set
+# `commons.timing.FAST_MODE` from test setup; off by default. not a config import.
+FAST_MODE = False
+
+UTC = timezone.utc
+
+# accepted timezone inputs: a tzinfo, an IANA name string, or None (-> UTC)
+TZ = Union[str, timezone, ZoneInfo, None]
+
+
+def _zone(tz: TZ):
+    """resolve a tz input (name / tzinfo / None) to a tzinfo, defaulting to UTC"""
+    if tz is None:
+        return UTC
+    if isinstance(tz, str):
+        return ZoneInfo(tz)
+    return tz
+
+
+def now() -> int:
+    """current unix timestamp as an int"""
+    return int(_time.time())
+
+
+def _delta_seconds(days: int, hours: int, minutes: int, seconds: int, fast: bool) -> int:
+    """seconds for a unit combination; collapses to 1s/unit when fast is True
+
+    single source of truth for unit math — every delta helper routes through here.
+    """
+    if fast:
+        return days + hours + minutes + seconds
+    return days * 86400 + hours * 3600 + minutes * 60 + seconds
+
+
+def add(
+    ts: int,
+    *,
+    days: int = 0,
+    hours: int = 0,
+    minutes: int = 0,
+    seconds: int = 0,
+    fast: Optional[bool] = None,
+) -> int:
+    """shift a unix timestamp by signed units (negatives subtract)"""
+    fast = FAST_MODE if fast is None else fast
+    return int(ts + _delta_seconds(days, hours, minutes, seconds, fast))
+
+
+def ahead(*, days: int = 0, hours: int = 0, minutes: int = 0, seconds: int = 0, fast: Optional[bool] = None) -> int:
+    """unix timestamp the given units in the future (now + delta)"""
+    return add(now(), days=days, hours=hours, minutes=minutes, seconds=seconds, fast=fast)
+
+
+def ago(*, days: int = 0, hours: int = 0, minutes: int = 0, seconds: int = 0, fast: Optional[bool] = None) -> int:
+    """unix timestamp the given units in the past (now - delta)"""
+    return add(now(), days=-days, hours=-hours, minutes=-minutes, seconds=-seconds, fast=fast)
+
+
+def is_expired(deadline: int) -> bool:
+    """True if a unix deadline has passed; a falsy/None deadline never expires"""
+    if not deadline:
+        return False
+    return now() > deadline
+
+
+def to_dt(ts: int, tz: TZ = None) -> datetime:
+    """convert a unix timestamp to an aware datetime in the given tz (default UTC)"""
+    return datetime.fromtimestamp(ts, _zone(tz))
+
+
+def to_unix(dt: datetime, tz: TZ = None) -> int:
+    """convert a datetime to a unix timestamp; naive inputs are read as tz/UTC"""
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=_zone(tz))
+    return int(dt.timestamp())
+
+
+def now_dt(tz: TZ = None) -> datetime:
+    """current time as an aware datetime in the given tz (default UTC)"""
+    return datetime.now(_zone(tz))
+
+
+def convert(dt: datetime, tz: TZ) -> datetime:
+    """re-express a datetime in another timezone (same instant, new wall clock)"""
+    return dt.astimezone(_zone(tz))
+
+
+def fmt(ts: int, tz: TZ = None, pattern: str = "%Y-%m-%d %H:%M:%S") -> str:
+    """format a unix timestamp in the given tz with an strftime pattern"""
+    return to_dt(ts, tz).strftime(pattern)
+
+
+def date(ts: Optional[int] = None, tz: TZ = None, pattern: str = "%m/%d/%Y") -> str:
+    """format the date portion of a timestamp (or now) in the given tz"""
+    return to_dt(now() if ts is None else ts, tz).strftime(pattern)
+
+
+class Clock:
+    """a timezone + fast-mode aware view over the same timing engine
+
+    construct with any IANA tz name (or tzinfo; default UTC) and an optional fast
+    flag. delta methods delegate to the module functions passing the clock's fast
+    setting; datetime methods produce values in the clock's timezone.
+    """
+
+    def __init__(self, tz: TZ = "UTC", *, fast: bool = False):
+        self.tz = _zone(tz)
+        self.fast = fast
+
+    def now(self) -> int:
+        """current unix timestamp (timezone-independent)"""
+        return now()
+
+    def add(self, ts: int, *, days: int = 0, hours: int = 0, minutes: int = 0, seconds: int = 0) -> int:
+        """shift a timestamp by signed units, honoring this clock's fast flag"""
+        return add(ts, days=days, hours=hours, minutes=minutes, seconds=seconds, fast=self.fast)
+
+    def ahead(self, *, days: int = 0, hours: int = 0, minutes: int = 0, seconds: int = 0) -> int:
+        """unix timestamp the given units in the future"""
+        return ahead(days=days, hours=hours, minutes=minutes, seconds=seconds, fast=self.fast)
+
+    def ago(self, *, days: int = 0, hours: int = 0, minutes: int = 0, seconds: int = 0) -> int:
+        """unix timestamp the given units in the past"""
+        return ago(days=days, hours=hours, minutes=minutes, seconds=seconds, fast=self.fast)
+
+    def is_expired(self, deadline: int) -> bool:
+        """True if a unix deadline has passed; falsy/None never expires"""
+        return is_expired(deadline)
+
+    def now_dt(self) -> datetime:
+        """current time as an aware datetime in this clock's timezone"""
+        return now_dt(self.tz)
+
+    def to_dt(self, ts: int) -> datetime:
+        """convert a unix timestamp to an aware datetime in this clock's timezone"""
+        return to_dt(ts, self.tz)
+
+    def to_unix(self, dt: datetime) -> int:
+        """convert a datetime to unix; naive inputs are read as this clock's tz"""
+        return to_unix(dt, self.tz)
+
+    def convert(self, dt: datetime) -> datetime:
+        """re-express any datetime in this clock's timezone (same instant)"""
+        return convert(dt, self.tz)
+
+    def fmt(self, ts: int, pattern: str = "%Y-%m-%d %H:%M:%S") -> str:
+        """format a unix timestamp in this clock's timezone"""
+        return fmt(ts, self.tz, pattern)
+
+    def date(self, ts: Optional[int] = None, pattern: str = "%m/%d/%Y") -> str:
+        """format the date of a timestamp (or now) in this clock's timezone"""
+        return date(ts, self.tz, pattern)