Hi @elmoujarrade and @Gassim,
There isn’t a quick solution in tracker to prevent this behavior. But it is possible with some program rule trickery.
Step 1: Create a date-type data element called VISIT DATE
Step 2: Create a program rule to ASSIGN the event date to the VISIT DATE Data element (expression is true)
Step 3: Create a program rule variable for the VISIT DATE in previous event, called PREVIOUS_EVENT_DATE
Step 4: Create a program rule to SHOW ERROR if V{event_date} = V{PREVIOUS_EVENT_DATE}. Text of the error message could be something like “An event for [stage name] already exists”
This should prevent users from entering two events with the same date into a repeatable stage.