ui update and some backend functionality adding in accordance with research on adhd and ux design

core/tz.py

@@ -0,0 +1,39 @@
+"""
+core/tz.py - Timezone-aware date/time helpers
+
+The frontend sends X-Timezone-Offset (minutes from UTC, same sign as
+JavaScript's getTimezoneOffset — positive means behind UTC).
+These helpers convert server UTC to the user's local date/time.
+"""
+
+from datetime import datetime, date, timezone, timedelta
+
+
+def _get_offset_minutes():
+    """Read the timezone offset header from the current Flask request.
+    Returns 0 if outside a request context or header is absent."""
+    try:
+        import flask
+        return int(flask.request.headers.get("X-Timezone-Offset", 0))
+    except (ValueError, TypeError, RuntimeError):
+        # RuntimeError: outside of request context
+        return 0
+
+
+def _offset_to_tz(offset_minutes):
+    """Convert JS-style offset (positive = behind UTC) to a timezone object."""
+    return timezone(timedelta(minutes=-offset_minutes))
+
+
+def user_now(offset_minutes=None):
+    """Current datetime in the user's timezone.
+    If offset_minutes is provided, uses that instead of the request header."""
+    if offset_minutes is None:
+        offset_minutes = _get_offset_minutes()
+    tz = _offset_to_tz(offset_minutes)
+    return datetime.now(tz)
+
+
+def user_today(offset_minutes=None):
+    """Current date in the user's timezone."""
+    return user_now(offset_minutes).date()