utcnow() doesn't take a specific date as the parameter. It takes a date format like this
utcNow('yyyy-MM-ddTHH:mm:ss')
If you want a future date then you need to use FormatDateTime and AddDays something like this
formatDateTime(addDays(utcNow(),22),'yyyy-MM-dd')
This would give you a date 22 days in the future from now.