Chnaging plan will affect my annual membership duration or not?

[DJVJ]

I want to change Creative cloud plan to photgraphy plan, my cloud plan will end on december 2021. If I change plan today, will it start a new 1 year cycle? I don't have use for CC but photography only. Will my plan duraition update or it will stay the same as right now?

[thatsmauri]

Your plan duration will indeed change.

What happens after you change your plan?

After you change your plan:

• The existing plan is cancelled, and you get the applicable refund for it.
• The new plan is effective immediately, and you receive a charge for the new plan.
• Your monthly billing date changes to the date you change your plan. 
• For yearly plans, the new renewal date is one year after the date you change your plan. For example, if you change your plan on June 14, 2019, the new plan renews on June 14, 2020.

Source: https://helpx.adobe.com/manage-account/using/change-plan.html