HI @makboga
How about this expression?
New DateTime(Now.Year, Now.Month, Now.Day) > New DateTime(Now.Year, Now.Month, 7) And New DateTime(Now.Year, Now.Month, Now.Day) < New DateTime(Now.Year, Now.Month, 30)
Workflow Screenshot
Then → DateTime.now.ToString("dd-MM-yyyy")
Else → (New DateTime(Today.AddMonths(1).Year,Today.AddMonths(1).Month,1)).AddDays(-1).toString("dd-MM-yyyy")
Output

Regards
Gokul
