Plugin doesn't handle DST

[Phlarx]

The plugin can be off by 1 hour due to daylight savings times changing out of sync

Original report by Shadefix (Suikertje)#0570 on the Openplanet discord, starting here: https://discord.com/channels/276076890714800129/276076890714800129/905978917784002570
(reported it for them, since they don't have a github account)

Suggestion: add an adjustment Setting that adds/subtracts hours, I guess?

[hmatt1]

@Phlarx thank you! I’ll take a look at it

[hmatt1]

I merged #2 to fix this issue, and uploaded version 0.2 to https://openplanet.nl/files/131 with the fix.