So if you think about it, this problem isn't that hard.So say it's 12:59, the total sum of those digits would be 71. if it was 1:11, then the sum would be 3. if it would be 3:47, the sum would be 50. So now, you have to find the time where it would be the least possible sum. That time would be 1:00 because 1+0+0=1.