OK, I started my diet on the 20th of last month. It has been exactly 4 weeks since that day. However, it is three more days till the 20th of THIS month. So I ask you, is today the month anniversary of my diet start, or is the 20th?

Is a month 4 weeks or 30 days?

I would go by dates because otherwise you'll end up with too many "months" eventually. I always figure out my kids' ages by date if I'm counting by months and that's how I'm figuring my diet, too. My monthly diet anniversary is the 26th.

22 pounds in a month is awesome, btw! I hope you feel really proud of yourself, that's wonderful.

thanks!

<Trivia queen chimes in>

A month is, on average, 4 1/3 weeks by the modern (solar based) calendar or 4 weeks by the lunar calendar. If you called 4 weeks a month you would still have 4 weeks left over at the end of the year and no months for them to go in.

So congratulations, you've lost that much in LESS than a month.

Yes, there are definitely two kinds of months. The crazy calendar months with 12 of them all having various days in them from 28 to 31, so it all "comes out right" and lunar months (the time system NATURE intended) that is every four weeks.)

I agree that your anniversary should be on the same date of the calendar month.

On that note I think that this is a fine example of how humans feel the need to complicate things. (by making up a calendar system that goes against natures calendar-the moon cycle is every 4 weeks, the menstrual cycle is every four weeks, a pregnancy is actually 10 lunar (four week) months starting from the woman's last period-not the close to 9 calendar months that we go by nowadays.
Going with nature is definitely much simpler.