Worked comparisons

Real pairs, clear reasoning

See how whole-hour, half-hour, calendar-day, and seasonal differences appear in ordinary planning.

Seasonal difference5 min example

Belgrade–Moscow time difference: 1 or 2 hours

Moscow is 2 hours ahead of Belgrade in winter and 1 hour ahead in summer. See why the exact Belgrade–Moscow difference depends on the date.

Half-hour offset5 min example

Asia/Kolkata uses a half-hour offset, while New York changes seasonally, so a whole-hour mental shortcut fails for this pair.