new timestamp feature and make tz data shared across cogs that need it

cogs/calendar.py

@@ -10,7 +10,7 @@ import discord
 from discord.ext import commands
 
 from firebase_website import get_db
-from .calendar_data import COUNTRY_TZ
+from .tz_data import COUNTRY_TZ, find_offset
 
 log = logging.getLogger(__name__)
 
@@ -22,23 +22,6 @@ TR_TZ = timezone(timedelta(hours=3))
 WH_NAME = "koharu"
 
 
-def _find_offset(country: str) -> float | None:
-    """Look up a country's UTC offset. Case-insensitive fuzzy match."""
-    c = country.strip().lower()
-    if not c:
-        return None
-    for name, offset in COUNTRY_TZ.items():
-        if c == name.lower():
-            return offset
-    for name, offset in COUNTRY_TZ.items():
-        if name.lower().startswith(c):
-            return offset
-    for name, offset in COUNTRY_TZ.items():
-        if c in name.lower():
-            return offset
-    return None
-
-
 # ==========================================
 # BOOK MODAL
 # ==========================================
@@ -130,7 +113,7 @@ class BookModal(discord.ui.Modal, title="Book an Event"):
             )
 
         # --- timezone lookup ---
-        offset = _find_offset(country)
+        offset = find_offset(country)
         if offset is None:
             return await interaction.response.send_message(
                 "Unknown country. Try: Turkey, UK, US East, Japan, etc.",