Earlier quoted context omitted.
"so I shouldn't have been able to click the days after today?" No, I did not get to that. I just fixed it so that if all the days you've clicked are after today (PST) then it does not try to calculate the streak of days between today and the beginning of time. And yeah, I was just lazy to not include timezones. I should fix that.
I have no idea if this is possible, but what about trying to read the timezone settings in the host computer with Javascript, rather than asking the user to set that?
Either do I but it would be just as easy to add a login, select timezone & store that, but then if you take a plane from foo to bar and your zones change you have to change it again.
This is a good idea btw. And I have looked at calendar apps in the past. The big PIA is time-syncing in with where you are at the moment.