One thing I do that makes me different to other people is I try to divide all units of time into 3. Perhaps because π is 3 and a bit, or perhaps because I think of three things at a time.
One month is roughly 30 days so the 'Alan week' is 10 days long.
Day 10 is ⅓ of a month.
Day 20 is ⅔ of a month
Day 30 (ish) is 1 month
The first 10 days of the month are the first third.
The 10 days after the 10th is the second third.
Then the days after the 20th are the final third.
I do the same with the clock on the wall.
20 minutes past is ⅓ of an hour
40 minutes past is ⅔ of an hour
The last 20 minutes is the final third of an hour.
I do the same with the calendar
The 4th month is ⅓ of a year
The 8th month is ⅔ of a year
The remaining 4 months are the last third of a year.
It's an Alan thing...