1. Added some more timezones, but not yet comprehensive I guess
2. Added work_week option for desktop
3. Same as 2
4. Maybe in the future? But I think my original goal was to avoid links so you can send self-contained availabilities in an email to someone
I noticed the "Copy" button generates a copy-pastable text. I was half expecting an encoded URL that one could share with people, they'd open this URL in their browser and see what the user just entered. For me at least it's easier to see a graphical calendar rather than trying to parse entries like "Friday May 1, 8:00-10:00."
The data doesn't even have to be stored server-side, you could encode the times and generate a URL with a "#", which the app would then decode so it could render the calendar with the markings.
Also, the URL to send the encoded calendar is a great idea! I've thought about doing that before, but focused on just creating the message because I thought users would rather just get the text and be done with the site, but I think I'll implement it and see if people use it