Clock utilities plugin is in beta, it may contain some bugs but they will eventually be fixed.
Clock utilities adds command /timer that creates timer with specified time to pass. When time passes, alarm rings to inform player that the time is over.
Command usage:
/timer <time in s> [time in m] [time in h]
permission:
clockUtilities.timer - allows to use /timer command (default)
This plugin is WIP, more content will be added soon. Please send your suggestions in the comments
Wiki:
https://github.com/Kartofel374/clockUtilities/wiki