Q:

How to improve a standard time-picking UX?

As part of a Sleep Tracking mobile app, I’m going to display users a summarized report which will include data about their Bed Time and Wake Up Time, according to my app’s estimations. I’d like to enable users to make corrections to this data, in case it’s inaccurate. The solution I have at the moment is an ‘Edit’ icon which will open up a time picker when tapped. However, I found that most users won’t really bother to tap it, and if they do, they will most likely just change one value (e.g. bed time) and not the other one.
I’m looking for other solutions, perhaps involving a custom UI picker, which will make the time-picking UX a bit more cool. An ideal solution would be one that won’t involve opening up a dialog (time picker). Any ideas?

A:

Does this need to be accurate down to the minute? Assuming the estimates provided by the app are within, say, one hour of the actual time, and if you're willing to sacrifice a degree of accuracy in favor of efficiency and ergonomics (very important for mobile), you could do away with the time picker altogether and simply provide up/down buttons that would allow me to increment/decrement the time in 15-minute increments.
E.g., here I'm looking at the estimated bed time:
Bed Time 11:45  [+] [-]

However, I actually went to bed around 10:15. I tap the minus button and see the value decrement to 11:30:
Bed Time 11:30 [+] [-]

I tap the minus button 5 more times to decrement the time to 10:15.
Dead simple for a mobile UI, but you would sacrifice some accuracy. You could shorten the increment to 10 minutes.

