use zoneinfo + tzdata

pytz stays around because of dependencies.
tzdata was also already transitively-required.

pyproject.toml

@@ -10,7 +10,6 @@ python = "^3.10"
 "discord.py" = "^2.3.2"
 icalendar = "^5.0"
 "python-dateutil" = "^2.9"
-pytz = "^2023.3"
 requests = "^2.31"
 beautifulsoup4 = "^4.12"
 APScheduler = "^3.10"
@@ -21,6 +20,7 @@ aio-mc-rcon = "^3.2.0"
 PyYAML = "^6.0"
 mcstatus = "^11.1.0"
 pillow = "^11.0.0"
+tzdata = "*"
 
 [tool.poetry.scripts]
 botdev = "dev.cli:main"

uqcsbot/utils/advent_utils.py

@@ -12,8 +12,8 @@
 )
 from collections import defaultdict
 from datetime import datetime, timedelta
+from zoneinfo import ZoneInfo
 from io import BytesIO
-from pytz import timezone
 
 import PIL.Image
 import PIL.ImageDraw
@@ -38,7 +38,7 @@
 Leaderboard = list[str | ColourFragment]
 
 # Puzzles are unlocked at midnight EST.
-EST_TIMEZONE = timezone("US/Eastern")
+EST_TIMEZONE = ZoneInfo("America/New_York")
 
 # The time to cache results to limit requests to adventofcode.com. Note that 15 minutes is the recomended minimum time.
 CACHE_TIME = timedelta(minutes=15)
@@ -95,7 +95,7 @@ def from_member_data(cls, data: Json, year: int) -> "Member":
             times = member.times[day]
 
             # timestamp of puzzle unlock (12AM EST)
-            DAY_START = EST_TIMEZONE.localize(datetime(year, 12, day))
+            DAY_START = datetime(year, 12, day, tzinfo=EST_TIMEZONE)
 
             for s, star_data in day_data.items():
                 star = int(s)