I believe God lives outside of the space-time he created. Therefore, he isn’t limited by time – as we are – so our prayers need not be bounded by time, either. This allows me to pray for things after the fact; the timing of when I pray is not as critical as the fact that I did pray, at some time.
For example, if someone asks for prayer at ten o’clock, I can pray at ten (the best option). Or I can pray in advance, anticipating what they will undergo (this is great if I’ll be busy at ten). A third option is to pray afterwards but to pray as if the outcome is still undetermined (this is hard and I don’t do it often).
Once I told a friend, I would pray for her – and then forgot. A reminder of my forgetfulness was an email from her, which essentially said, “thanks for praying; things didn’t work out.”
Dismayed over my broken promise, I did my best to set aside my knowledge of the outcome and pray as if it hadn’t occurred. My faith, that my feeble prayer would be answered, was weak at best, but I did pray nonetheless. About four hours later I received a second email, which negated the first. It basically said, “God is amazing; he has provided for me and answered our prayers.”
I can’t explain the two contradicting emails and don’t know the details. What I do know is that God answers our prayers – regardless of when we pray.