Add timezone and DST support by samcorky · Pull Request #20 · sjefferson99/pico-clock

samcorky · 2026-02-18T19:56:40Z

This PR adds timezone support so the clock can display local time based on a configured IANA timezone (or default to UTC when unset/unknown).

What’s included

TIMEZONE config option (IANA name; None = UTC)
Timezone module that maps IANA → POSIX TZ and converts epoch/time tuples into localized time (including DST rules where applicable)
Clock display updates now use localized time/date values

If the configured timezone isn’t recognised, the clock falls back to UTC.

Need to make it output to the display and optimise it - only re-calc every minute

…atting support

…ased methods

Copilot

Pull request overview

Adds a lightweight timezone layer to the Pico Clock so displayed time/date can be localized from a configured IANA timezone (with DST where applicable), falling back to UTC when unknown.

Changes:

Introduces a timezone package with an IANA→POSIX mapping and POSIX TZ conversion utilities.
Adds a TIMEZONE config option and wires localization into the clock display update loop.
Expands .gitignore to exclude common local/dev artifacts.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
`src/lib/timezone/localPZtime.py`	POSIX TZ parsing/conversion implementation used to compute localized time/DST.
`src/lib/timezone/db.py`	Embedded IANA→POSIX timezone mapping plus lookup helper.
`src/lib/timezone/__init__.py`	`Timezone` wrapper that selects a POSIX string and converts tuples/epochs to local time.
`src/lib/clock.py`	Uses `Timezone` to localize `TimeSource` output before updating displays.
`src/config.py`	Adds `TIMEZONE` configuration value.
`.gitignore`	Ignores venv/IDE and Python lock/config files.

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Copilot · 2026-02-18T20:49:29Z

+
+	:author:	Roberto Bellingeri
+	:copyright:	Copyright 2023 - NetGuru
+	:license:	GPL


The file header declares :license: GPL and includes a third‑party copyright notice, while the repository root LICENSE is MIT. Please confirm the provenance and licensing is compatible with this repo, or replace/rewrite this module under an MIT-compatible license before merging.

Suggested change

:author: Roberto Bellingeri

:copyright: Copyright 2023 - NetGuru

:license: GPL

@samcorky my code is MIT so this will need resolving,

Copilot · 2026-02-18T20:49:29Z

+            stx += f"{(tx[9] // 3600):+03d}"
+
+            mins = abs(tx[9]) % 3600
+            if (mins != 0):
+                stx += ":" + f"{(mins // 60):02d}"


tziso() formats the UTC offset hours using floor division (tx[9] // 3600). For negative offsets with minutes (e.g. UTC−03:30), floor division rounds down and produces an incorrect hour (−04), yielding the wrong ISO8601 offset string. Compute hours/minutes using absolute values + sign (or truncation toward zero) to avoid this.

Suggested change

stx += f"{(tx[9] // 3600):+03d}"

mins = abs(tx[9]) % 3600

if (mins != 0):

stx += ":" + f"{(mins // 60):02d}"

# tx[9] is the UTC offset in seconds; compute sign, hours, and minutes

total_seconds = abs(tx[9])

hours = total_seconds // 3600

mins = (total_seconds % 3600) // 60

sign = 1 if tx[9] >= 0 else -1

stx += f"{sign * hours:+03d}"

if (mins != 0):

stx += ":" + f"{mins:02d}"

Copilot · 2026-02-18T20:49:30Z

+## Timezone in IANA format
+TIMEZONE = "Etc/UTC"
+


The default TIMEZONE value ("ETC/UTC") does not match the IANA casing used by the timezone database keys (e.g. "Etc/UTC"). This will always trigger the "not found" fallback path and log a warning on every boot with the default config. Use the correct canonical IANA ID or normalize input before lookup.

Copilot · 2026-02-18T20:49:30Z

+import time
+


import time is added but not used anywhere in this file; please remove it to avoid dead imports.

Suggested change

import time

Copilot · 2026-02-18T20:49:30Z

+import time
+
+from lib.timezone import localPZtime
+from lib.timezone.db import TIMEZONE_TO_POSIX, timezone_to_posix


TIMEZONE_TO_POSIX is imported here but never used; please remove the unused import to keep the module minimal (especially important on MicroPython targets).

Suggested change

from lib.timezone.db import TIMEZONE_TO_POSIX, timezone_to_posix

from lib.timezone.db import timezone_to_posix

Copilot · 2026-02-18T20:49:31Z

+    def epoch_to_local_time_iso8601(self, time_tuple: tuple) -> str:
+        """
+        Convert time tuple to ISO8601 formatted local time string
+        """
+        # Pad time_tuple with 0s up to 8 elements
+        padded_time_tuple = time_tuple + (0,) * (8 - len(time_tuple))
+
+        epoch = time.mktime(padded_time_tuple)
+        local_time = localPZtime.tziso(epoch, self.posix_str)
+        return local_time


Method name epoch_to_local_time_iso8601 is misleading: it accepts a time tuple (not an epoch) and internally calls time.mktime to compute an epoch. Rename it (e.g. time_tuple_to_local_time_iso8601) or change the parameter to an epoch seconds value to match the name/docstring.

…imports

…is GPL so cannot be included

samcorky · 2026-04-16T15:39:55Z

The https://github.com/samcorky/utimezone.git repository is almost ready.

samcorky added 3 commits February 11, 2026 21:39

Started timezone support - can go from time tuple -> epoch -> local time

bb2c4ef

Need to make it output to the display and optimise it - only re-calc every minute

Refactor time conversion to use epoch-based methods; add ISO8601 form…

61d605e

…atting support

Refactor time handling to use local time conversions; replace epoch-b…

02b4839

…ased methods

sjefferson99 reviewed Feb 18, 2026

View reviewed changes

Comment thread src/lib/timezone/__init__.py

Set default timezone to UTC; simplify timezone initialization logic

10329c0

sjefferson99 self-assigned this Feb 18, 2026

sjefferson99 requested a review from Copilot February 18, 2026 20:44

Copilot started reviewing on behalf of sjefferson99 February 18, 2026 20:45 View session

Fix case in default timezone configuration ("ETC/UTC" -> "Etc/UTC")

03ef607

Copilot AI reviewed Feb 18, 2026

View reviewed changes

Refactor timezone handling: rename method for clarity, remove unused …

8f686f2

…imports

samcorky marked this pull request as draft February 18, 2026 21:26

samcorky added 2 commits February 18, 2026 21:27

Start custom timezone conversion logic - for MIT repo. Existing code …

7646101

…is GPL so cannot be included

Start custom timezone conversion logic - for MIT repo. Existing code …

2c156f1

…is GPL so cannot be included

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Add timezone and DST support#20

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-            stx += f"{(tx[9] // 3600):+03d}"
-            mins = abs(tx[9]) % 3600
-            if (mins != 0):
-                stx += ":" + f"{(mins // 60):02d}"
+            # tx[9] is the UTC offset in seconds; compute sign, hours, and minutes
+            total_seconds = abs(tx[9])
+            hours = total_seconds // 3600
+            mins = (total_seconds % 3600) // 60
+            sign = 1 if tx[9] >= 0 else -1
+            stx += f"{sign * hours:+03d}"
+            if (mins != 0):
+                stx += ":" + f"{mins:02d}"

	from lib.timezone.db import TIMEZONE_TO_POSIX, timezone_to_posix
	from lib.timezone.db import timezone_to_posix

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samcorky commented Feb 18, 2026

What’s included

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