1.21.2 - Major Maintenance Bug Fix

🐻 Always perform a backup of your Uptime Kuma before upgrading.

⚠️ IMPORTANT

After upgraded to this version. You should review your maintenance:

• All old maintenance schedules will be set to UTC individually, if you need other timezones, please change it individually.
• Since previous versions' maintenance is always respected to UTC, which means the maintenance time could be shifted due to DST in your country. You should check it.
• Breaking change: Due to the limitation of cron, the options Last 2nd day of month, Last 3rd day of month and Last 4th day of month in the strategy Day of Month is no longer available. (Last day of month is still available)

🆕 New Features

• Now you can schedule maintenance with a cron expression + duration

🐛 Bug Fixes

• #3003 Maintenance is completely bugged in 1.21.1 and 1.21.0
• #2988 Fix Ignore TLS/SSL Error is not working when using a proxy (Thanks @chakflying)

💇‍♀️ Improvements

• [Maintenance] The core of maintenance feature is completely rewritten and is changed to cron based, the performance is much better
• [Maintenance] Effective Date Range is no longer required, it is now optional
• [Maintenance] Ability to set a timezone per maintenance
• [Maintenance] Ability to follow the timezone with DST

🦎 Translation Contributors

• #3015 (Thanks @Buchtic @Genc @ademaro @aljvdi @cyril59310 @filename24 @ismael1222 @marco-doerig @rubesaca)

Others

• It no longer perform a backup during a database migration, so it won't take up a lot of disk space unexpectedly if your database is big. However, I highly recommended that you should backup manually.
• Other small changes, code refactoring and helps:
  @GrantBirki
  (Let me know if your name is missing. If your pull request have been merged in this version)