>>324023229
>>324024173
Well I fixed it no thanks to moment.js/luxon having slightly different timezone names.

SOS Speed Dating - SEA - 5PM GMT+8 February 13
https://vrg.party/countdown.html?d=2021-02-13T17%3A00%3A00.000-08%3A00&z=Etc%2FGMT%2B8
SOS Speed Dating - EU - 9PM GMT+1 February 13
https://vrg.party/countdown.html?d=2021-02-13T21%3A00%3A00.000-01%3A00&z=Etc%2FGMT%2B1
SOS Speed Dating - NA - 10:30PM EST February 13
https://vrg.party/countdown.html?d=2021-02-13T22%3A30%3A00.000-05%3A00&z=EST

>>324024320
in theory moment's tzdata will switch over the regional timezones (e.g. US/Eastern) from EST/EDT once it happens, we'll see. At least you'll be able to check if the times in other zones are as you expect.