The two zones in context
UTC vs PDT — cities and working rhythm
UTC — Coordinated Universal Time
Primary cities: Reference clock — aviation, IT logs, science, distributed teams
UTC is the reference offset — not a civil timezone anywhere, but the standard for aviation ("Zulu time"), server logs, astronomy, and cross-timezone team calendars. When distributed engineering teams schedule "the daily standup at 15:00 UTC" they're dodging the DST-flip mess entirely.
PDT — Pacific Daylight Time
Primary cities: Los Angeles, San Francisco, Seattle, Vancouver (summer)
US West Coast summer offset (mid-March to early November), UTC-7. During PDT, the 7-h gap with UTC / London simplifies daylight-hour overlap — 9 AM PT = 5 PM London (BST).
Time gap: PDT is 7.0 hours behind UTC (standard-time offsets — daylight-saving flips shift this by an hour twice a year in most northern-hemisphere zones).