masudrhossain

[sleek depot]

Hello, yes, you can modify the billing cycle anchor. For existing subscriptions you can only set it to the current time https://stripe.com/docs/billing/subscriptions/billing-cycle

Current period end will change along with the billing cycle anchor or if you change the price on the subscription to a price with a different cycle length

You may also find our test clocks helpful, they let you simulate time passing to see how subscriptions would work over time https://stripe.com/docs/api/test_clocks

[wary helm]

If i add a trial_days, when does it update the billing_cycle_anchor and current_period_end?

Test clocks is what i was looking for too, thanks

[sleek depot]

According to that doc, when you set a trial, the billing cycle anchor is automatically set to be the end of the trial

Add a trial: this automatically sets the anchor date to the end of the trial. Trials typically start when you create a subscription, but you can also apply them to existing subscriptions. You can change a subscription’s billing cycle using a trial through the API or the Dashboard.

[wary helm]

So right away

[sleek depot]

Correct