With Linux, you can simply make a crontab every day at 6:00 am, kills the srcds_linux program.
The srcds_run "wrapper" will automatically re-start it after 10 seconds.
Easy way, without the need of a plugin. Although no messages will be shown, and players will time out like if the server crashed.
- [ANY] Server Crontab
- [ANY] Full Cronjob Plugin [Execute commands on time intervals / game events]
Here you can set it to every minute (e.g. for the 5 minutes before), a message will be printed, until it at the 6th time, it will just execute "quit", which would again make the srcds_run wrapper auto-restart the server (with Linux at least).
So like set to make "sm_msay" or something at 5:55, 5:56, 5:57, 5:58 and 5:59, then to "quit" at 6:00.