So you want to answer the questions 'when did i fall sleep last night?' and 'did i get enough sleep?' I have to wonder why.
It suggests you are wanting to ensure you get a healthy amount of sleep by getting the answers to these questions. But really, you don't need to answer these questions at all. Instead just time-box the amount of sleep you should have (whatever you determine that to be) and then just set alarms on your phone/laptop around your schedule to instruct you when to go to bed and when to sleep - sorted.
I sense your overly elaborate, approximate solution to your problem is a result of you suffering from sleep deprivation! ;)
It suggests you are wanting to ensure you get a healthy amount of sleep by getting the answers to these questions. But really, you don't need to answer these questions at all. Instead just time-box the amount of sleep you should have (whatever you determine that to be) and then just set alarms on your phone/laptop around your schedule to instruct you when to go to bed and when to sleep - sorted.
I sense your overly elaborate, approximate solution to your problem is a result of you suffering from sleep deprivation! ;)