We are trying to setup a recurring payment for a daily subscription for 7 days ideally at specific time or window (within 4 hours) every night. Paypal told they can't do specific time; however, it will be done at same time based on when customer signs up. Now few did occur as stated and few didn't occur. I will appreciate if someone has a recommendation of a solution
Most payment processors on the internet have a Recurring Billing option to bill for a specific interval for a specific recurrence count. I recall Authorized.net specifically does it and can meet PCI compliance. Most processors offer recurring option but may not provide a daily option. You may need to a custom solution such as Authorized.net Customer Information Manager (CIM) for dynamic recurring billing (you bill your customers different amounts or on different days each month).
Stripe has a daily subscription plan option that you can easily integrate with (hint: our innovation platform at https://www.chimi.co supports it out-of-the-box). While you can't tell it at which time of the day to process the payments, they would typically fall in (similar to your comment, but should actually work) around 24 hour multiples of the subscription creation time. I haven't tested this myself but, in addition, if you (programmatically) delay the subscription to be created within your time window, then the following daily recurring payments should also fall within that same time window.
Hope this helps!
It looks like you're trying to find a service that will allow you to pre-set the execution time of your payment, which is very uncommon. Typically they use recurrent payments to even out fluctuations in traffic on their servers, allowing them to execute them at will (and unpredictably).
If you really do need it to be at an exact time, I'd recommend creating a script to do it for you. They're pretty simple to create.