worlflow clarifications

in stock SuiteCRM, the calls are automatically created with future date whenever a new contract is created. i want to create a call only if the renewal date is equals to today. i setup workflow as attached screenshot, but my workflow is not firing. pl see the attachment

my cron is set to run every 12hrs.

Is it due to cron to set to run every 12 hrs?

how the “now” is calculated in AOS Workflow? is it at midnight? if the midnight is elasped when cron is set to run, what will happen to workflow?

in workflow checkbox “Repeated Runs:” is it required to be checked when i want this process to run whenever my cron job is run? the “repeat run” is for the process or records?

anyone?