Which zone this page means. GMT and UTC are the same offset but not the same thing: GMT is a time zone, UTC is a time standard. The United Kingdom is on GMT in winter and BST (UTC+1) in summer. PST is standard time only. From the second Sunday in March to the first Sunday in November the Pacific zone is on PDT (UTC-7). Most people write PST year-round.
GMT is ahead of PST by 7 hours today
On 19 August 2026, Greenwich Mean Time is on GMT at UTC+00:00 and Pacific Standard Time is on PDT at UTC-07:00. The gap between them is 7 hours, with PST behind. So 9:00 am in GMT is 2:00 am in PST, and 5:00 pm in GMT is 10:00 am in PST. Going the other way, see PST to GMT.
The gap is not constant, and that is the part that catches people out
Pacific Standard Time is currently observing daylight saving and changes next on 1 November 2026. Greenwich Mean Time does not observe daylight saving, so the gap moves only when Pacific Standard Time changes its clocks — twice a year, by one hour.
When you can actually both be at work
Taking a working day as 9:00 am to 5:00 pm local at each end, there is 1 overlapping hour in a normal day. In GMT that window runs from 4:00 pm to 5:00 pm, which is 9:00 am to 10:00 am in PST. Anything outside it needs one side to start early or finish late.
Zone rules are set by legislation and change, sometimes at short notice. This page is built against tzdata 2026a, last reviewed 2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads your browser's own copy of the zone database, so if a rule has changed since this page was built the live answer follows the new rule.
Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the daylight-saving rules behind the 7-hour gap above.