SQL calculates the start annual leave based on the work day.

-- Calculate the start annual leave based on the working day
Declare @ settoday smalldatetime, @ birthday smalldatetime, @ year varchar (10), @ month varchar (10), @ day varchar (10), @ enddate datetime, @ Stardate datetime, @ annualnumber int, @ annualtotal int, @ surplus int
Set @ settoday = '2014-05-04 '-- current date
Set @ Birthday = '2017-04-26 '--- company date
Set @ year = datename (year, @ settoday)
Set @ month = datename (month, @ birthday)
Set @ day = datename (day, @ birthday)
--
Set @ enddate = cast (@ year + '-' + @ month + '-' + @ day as datetime)
Select @ month
Select @ enddate
If (@ enddate >=@ settoday)
Begin
Set @ Stardate = dateadd (year,-1, @ enddate) -- renew for one year
End
Else
Begin
Set @ enddate = dateadd (year, 1, @ enddate)
Set @ Stardate = cast (@ year + '-' + @ month + '-' + @ day as datetime)
End
Select @ Stardate as 'start calculation date'
Select @ enddate as 'end calculation date'