I’ve created a formula to subtract no.of days from a date, this has worked, however a number of the fields are blank so returning an error, I’ve created a separate formula for that too which also works, but I don’t know how to join them together in the same formulae?
DATEADD({Date auto-renew goes into effect},-{Auto renew notice period},‘days’)
IF({Date auto-renew goes into effect}, " ")