iCall Trigger event for executing a command

you can use periodic and use the options to make it sure it only runs once (ie first-occurrence, high interval and last-occurrence) , see the example and your options here:

https://devcentral.f5.com/s/articles/third-times-the-charm-big-ip-backups-simplified-with-icall

root@(ltm2)(cfg-sync Standalone)(Active)(/Common)(tmos)# create sys icall handler periodic testme ? 
Identifier: 
  [object identifier]  Specify a name for the handler item 
Properties: 
  "{"                  Optional delimiter 
  app-service 
  arguments            Specifies a set of name/value pairs to be passed in as data to the script for every execution 
  description          User defined explanation of the item 
  first-occurrence     Specifies the date and time of the first occurrence this handler should execute 
  interval             Specifies the number of seconds between each occurrence of this handler's automatic execution 
  last-occurrence      Specifies the date and time after which no more occurrences will execute 
  script               Specifies the handler's script to execute upon invocation 
  status               Manage the perpetual process by specifying active or inactive