are you high? March 2009 - March 2010 one year, March 2010- March 2011- two years, March 2011 to May 2012 is three years
https://www.timeanddate.com/date/durationresult.html?m1=03&d1=01&y1=2009&m2=05&d2=01&y2=2012&h1=&i1=&s1=&h2=&i2=&s2=
From: Sunday, March 1, 2009 at 12:00:00 midnight
To: Tuesday, May 1, 2012 at 12:00:00 midnight
Result: 1157 days, 0 hours, 0 minutes and 0 seconds
The duration is 1157 days, 0 hours, 0 minutes and 0 seconds
Or 3 years, 2 months excluding the end date.
Or 38 months excluding the end date.
Alternative time units
1157 days, 0 hours, 0 minutes and 0 seconds can be converted to one of these units:
99,964,800 seconds
1,666,080 minutes
27,768 hours
1157 days
165 weeks and 2 days
316.99% of a common year (365 days)