Use aware objects when storing and reading UTC timestamps (#4017)

* Use aware objects instead of naive ones

* Use aware objects when storing and reading UTC timestamps

* Remove unneeded parentheses

* Fixed naive and aware objects unable to be compared here

* Address feedback

* Fix the newly added `modlog.create_case()` calls

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

redbot/core/bank.py

@@ -1,8 +1,8 @@
 from __future__ import annotations
 
 import asyncio
-import datetime
 import logging
+from datetime import datetime, timezone
 from typing import Union, List, Optional, TYPE_CHECKING, Literal
 from functools import wraps
 
@@ -109,7 +109,7 @@ class Account:
 
     This class should ONLY be instantiated by the bank itself."""
 
-    def __init__(self, name: str, balance: int, created_at: datetime.datetime):
+    def __init__(self, name: str, balance: int, created_at: datetime):
         self.name = name
         self.balance = balance
         self.created_at = created_at
@@ -117,25 +117,25 @@ class Account:
 
 def _encoded_current_time() -> int:
     """Get the current UTC time as a timestamp.
-    
+
     Returns
     -------
     int
         The current UTC timestamp.
 
     """
-    now = datetime.datetime.utcnow()
+    now = datetime.now(timezone.utc)
     return _encode_time(now)
 
 
-def _encode_time(time: datetime.datetime) -> int:
+def _encode_time(time: datetime) -> int:
     """Convert a datetime object to a serializable int.
-    
+
     Parameters
     ----------
     time : datetime.datetime
         The datetime to convert.
-        
+
     Returns
     -------
     int
@@ -146,21 +146,21 @@ def _encode_time(time: datetime.datetime) -> int:
     return ret
 
 
-def _decode_time(time: int) -> datetime.datetime:
+def _decode_time(time: int) -> datetime:
     """Convert a timestamp to a datetime object.
-    
+
     Parameters
     ----------
     time : int
         The timestamp to decode.
-        
+
     Returns
     -------
     datetime.datetime
         The datetime object from the timestamp.
 
     """
-    return datetime.datetime.utcfromtimestamp(time)
+    return datetime.utcfromtimestamp(time)
 
 
 async def get_balance(member: discord.Member) -> int:

redbot/core/events.py

@@ -3,10 +3,9 @@ import contextlib
 import platform
 import sys
 import codecs
-import datetime
 import logging
 import traceback
-from datetime import timedelta
+from datetime import datetime, timedelta
 
 import aiohttp
 import discord
@@ -55,7 +54,7 @@ def init_events(bot, cli_flags):
         if bot._uptime is not None:
             return
 
-        bot._uptime = datetime.datetime.utcnow()
+        bot._uptime = datetime.utcnow()
 
         guilds = len(bot.guilds)
         users = len(set([m for m in bot.get_all_members()]))
@@ -313,7 +312,7 @@ def init_events(bot, cli_flags):
             not bot._checked_time_accuracy
             or (discord_now - timedelta(minutes=60)) > bot._checked_time_accuracy
         ):
-            system_now = datetime.datetime.utcnow()
+            system_now = datetime.utcnow()
             diff = abs((discord_now - system_now).total_seconds())
             if diff > 60:
                 log.warning(

redbot/core/modlog.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import asyncio
 import logging
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from typing import List, Literal, Union, Optional, cast, TYPE_CHECKING
 
 import discord
@@ -127,7 +127,8 @@ async def _init(bot: Red):
                 if entry:
                     if entry.user.id != guild.me.id:
                         # Don't create modlog entires for the bot's own bans, cogs do this.
-                        mod, reason, date = entry.user, entry.reason, entry.created_at
+                        mod, reason = entry.user, entry.reason
+                        date = entry.created_at.replace(tzinfo=timezone.utc)
                         await create_case(_bot_ref, guild, date, "ban", member, mod, reason)
                     return
 
@@ -163,7 +164,8 @@ async def _init(bot: Red):
                 if entry:
                     if entry.user.id != guild.me.id:
                         # Don't create modlog entires for the bot's own unbans, cogs do this.
-                        mod, reason, date = entry.user, entry.reason, entry.created_at
+                        mod, reason = entry.user, entry.reason
+                        date = entry.created_at.replace(tzinfo=timezone.utc)
                         await create_case(_bot_ref, guild, date, "unban", user, mod, reason)
                     return
 
@@ -351,9 +353,9 @@ class Case:
         until = None
         duration = None
         if self.until:
-            start = datetime.fromtimestamp(self.created_at)
-            end = datetime.fromtimestamp(self.until)
-            end_fmt = end.strftime("%Y-%m-%d %H:%M:%S")
+            start = datetime.utcfromtimestamp(self.created_at)
+            end = datetime.utcfromtimestamp(self.until)
+            end_fmt = end.strftime("%Y-%m-%d %H:%M:%S UTC")
             duration = end - start
             dur_fmt = _strfdelta(duration)
             until = end_fmt
@@ -374,7 +376,7 @@ class Case:
         last_modified = None
         if self.modified_at:
             last_modified = "{}".format(
-                datetime.fromtimestamp(self.modified_at).strftime("%Y-%m-%d %H:%M:%S")
+                datetime.utcfromtimestamp(self.modified_at).strftime("%Y-%m-%d %H:%M:%S UTC")
             )
 
         if isinstance(self.user, int):
@@ -413,7 +415,7 @@ class Case:
                 emb.add_field(name=_("Amended by"), value=amended_by)
             if last_modified:
                 emb.add_field(name=_("Last modified at"), value=last_modified)
-            emb.timestamp = datetime.fromtimestamp(self.created_at)
+            emb.timestamp = datetime.utcfromtimestamp(self.created_at)
             return emb
         else:
             user = filter_mass_mentions(filter_urls(user))  # Further sanitization outside embeds