The Time Zone Problem


Time zones and the British perspective
San Francisco (Where Linden Labs are based) has Pacific Daylight Time (PDT) and the United Kingdom has Greenwich Mean Time (GMT). Normally, PDT is eight hours behind GMT. So, if it’s 6.00pm in the UK, then it’s 10.00am in San Francisco. Except when it isn’t, which is usually for two or three weeks each spring and one week each autumn.

Both places move forward an hour each spring and back an hour each autumn. Even if both places did that on the same day each year we would still need to have this conversation, because the shift would take place at different times in each place, so we would still be out of synch, but only for a few hours instead of weeks.

SPRING
In spring, the USA tends to adopt Daylight Saving Time (DST) a couple of weeks before the UK moves to British Summer Time (BST). So, during the interval, if you’re in the UK and you’re attending an event in Second Life, you can show up an hour LATER, because, for a couple (or three) weeks the time zone difference between the two places is nine hours.

2019
PDT gains DST on Sunday 10th March
GMT goes to BST on Sunday 31st March

2020
PDT gains DST on Sunday 8th March
GMT goes to BST on Sunday 29th March

2021
PDT gains DST on Sunday 14th March
GMT goes to BST on Sunday 28th March

If the event is on either of those dates, tread carefully (or cancel your plans and have a day off), because the time shifts in each place is at different times, relative to each other.

AUTUMN (FALL, WHATEVER)
In autumn the UK reverts to GMT a week or so before San Francisco goes back to PDT. During that interval, if you’re in the UK and you attend an event in Second Life, you need to show up an hour EARLIER, because for that short period the time zone difference is only seven hours.

2019
BST goes to GMT on Sunday 27th October
PDT loses DST on Sunday 7th November

2020
BST goes to GMT on Sunday 25th October
PDT loses DST on Sunday 1st November

2021
BST goes to GMT on Sunday 31st October
PDT loses DST on Sunday 7th November

If the event is on either of those dates, tread carefully (or cancel your plans and have a day off), because the time shifts in each place is at different times relative to each other.