jiff::civil::date

Function month_add_one

Source 
fn month_add_one(
    year: ri16<-9999, 9999>,
    month: ri8<1, 12>,
    delta: ri8<-1, 1>,
) -> Result<(ri16<-9999, 9999>, ri8<1, 12>), Error>
Expand description

Adds or subtracts sign from the given year/month.

If month overflows in either direction, then the year returned is adjusted as appropriate.