• Change field DateA from text to date
• Change calculation for DateB to :
If ( Self ≤ DateA ; DateA -134 ; Self )
Keep "Calculation result is Date"
Self won't work in a field of type calculation.
But be sure to leave the "do not evaluate if all referenced fields are empty." check box selected so that you don't in up with an invalid date if no date has been entered into DateA.
its works guys thanks