Our thanks to Chicago NA for this clean time calculator!

There may be some confusion as to how we calculate cleantime. We do it exactly the same way that it's done in NA meetings:

1. If the cleantime is less than, or equal to, 90 days:
   Here, we count days. Months and dates don't really come into play. This means that 30 days is actually 30 days. February 15th to March 15th is 28 days in a non-leap year, and 29 days in a leap year. You don't get 30 days until March 16th or 17th. (Depending on whether it's a leap year or not.)


2. If the cleantime is greater than 90 days:
   Here, we count by dates. This means that February 15th to June 15th is considered 4 months and February 15th to August 15th is 6 months exactly. February 15th to August 31st is 6 months and 16 days. February 15th to September 1st is 6 months and 17 days. You don't have 7 months until September 15th. February 15th to May 16th is 90 days, but February 15th to May 17th is 3 months and 2 days.