Hi Mario,
I am not aware of a solution - thus the proposed feature Dynamic ("Calculated") Values in Campaign Actions
What we do as a workaround is to store the date&time when the form has been sent (https://www.leuchtfeuer.com/en/mautic-know-how/mautic/dynamic-values-in-mautic-forms-date-time-url)
Best,
Ekke
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