2207 is military time 2207 is 10 hours and 7minutes past 12 (12 would be 1200) So it was 10:07 pm when Marla went to bed so Adelaide went to bed earlier
Do you mean 22:07? If so, then Marla went to bed in army time, which carries on from 12 o'clock. So 22:07 in army time is 10:07 PM, so Adelaide went to be earlier.
