Which zone this page means. 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 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 behind GMT by 7 hours today
On 19 August 2026, Pacific Standard Time is on PDT at UTC-07:00 and Greenwich Mean Time is on GMT at UTC+00:00. The gap between them is 7 hours, with GMT ahead. So 9:00 am in PST is 4:00 pm in GMT, and 5:00 pm in PST is 12:00 am in GMT. Going the other way, see GMT to PST.
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, when clocks go back an hour. Greenwich Mean Time does not observe daylight saving at all, so the whole of the seasonal change comes from the PST side: the gap moves by an hour twice a year even though nothing changes in Greenwich Mean Time.
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 PST that window runs from 9:00 am to 10:00 am, which is 4:00 pm to 5:00 pm in GMT. 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.