Time zones, UTC and DST — the 5-minute explainer

Coordinating a call between New York, London and Tokyo shouldn't require mental gymnastics. A little theory makes time conversion easy.

UTC is the anchor

UTC (Coordinated Universal Time) is the global reference clock — everything else is an offset from it, like UTC+1 (Paris in winter) or UTC−5 (New York in winter). Knowing offsets makes conversions a simple sum.

Daylight saving time

DST shifts many regions by an hour twice a year — but not all (Arizona, most of Asia). Offsets you memorized in summer may be wrong in winter, which is exactly where our time zone converter helps: DST rules are applied automatically.

Pick a universal convention

For team calls, state times in UTC or a single agreed time zone. Tools like the world clock comparison (up to 4 cities at once) remove the guesswork entirely.