======Synopsis:======
[[on]] [#][<mode>]timer [<serial#>] [-|^]<match> { <action> }

======Description:======
This hook is triggered whenever the specified time (or time glob pattern)
matches the current time.  The time may be in one of two formats:

^Format             ^Description                                            ^
|hh:mm<am%%|%%pm>   |0 <= hh <= 12, 0 <= mm <= 59, am or pm set accordingly |
|hh:mm              |0 <= hh <= 23, 0 <= mm <= 59                           |

======Parameters:======
|$0 |current time (format depends on [[set CLOCK_24HOUR|CLOCK_24HOUR]] setting)|

======Examples:======
To inform the user of the time once per hour on the hour:
   on ^timer "%:00*" {
      xecho -b The time is now $Z
      beep
   }