Calculate number of months between two dates yyyyMm, yyyy.m or yyyy-mm-dd

Usage

nmons(dat1 = "", dat2 = "")

Arguments

dat1: date of period start (string: yyyyMm, yyyy.m, or yyyy-mm-dd)
dat2: date of period end (string: yyyyMm, yyyy.m, or yyyy-mm-dd)

Value

numeric length of date range in months

Details

The endpoints are included in the result so subtract one for time difference. Also, the result is rounded down so partial months are not counted. See examples.

Examples

nmons("2010M1", "2010M2")
#> [1] 4
nmons(2010.1, 2010.4)
#> [1] 10
nmons("2010-01-15", "2010-04-15")
#> [1] 4
nmons("2010-01-15", "2010-04-18")
#> [1] 4
nmons("2010-01-15", "2010-04-12")
#> [1] 3