Apple TV Subsription

As far as I can tell there is only a 3 months offer now.

Click on the link and read it, including the FAQ at the end. Check your eligibility. --> https://offers.appletvapp.apple/

Apple TV+ offer - Terms and conditions US

https://www.apple.com/promo/pdf/EN_US_ATV+_Promo_TandCs.pdf

'If you can't redeem your promotional trial of Apple TV+' click here --> https://support.apple.com/HT211767

How do I find out when my Appletv free subscription is due?

Your subscriptions overview would list the next billing date for each subscription, if that is what you mean.

You would also have received a confirmation email, directly after signup, with these details.

How do I find out when my Appletv free subscription is due?