declare @Birthdate datetime
declare @AsOnDate datetime
declare @years int
declare @months int
declare @days int
declare @hours int
declare @minutes int
--NOTE: date of birth must be smaller than As on date,
--else it could produce wrong results
set @Birthdate = '1989-11-30 9:27 pm' --birthdate
set @AsOnDate = Getdate() --current datetime
--calculate years
select @years = datediff(year,@Birthdate,@AsOnDate)
--calculate months if it's value is negative then it
--indicates after __ months; __ years will be complete
--To resolve this, we have taken a flag @MonthOverflow...
declare @monthOverflow int
select @monthOverflow = case when datediff(month,@Birthdate,@AsOnDate) -
( datediff(year,@Birthdate,@AsOnDate) * 12) <0 then -1 else 1 end
--decrease year by 1 if months are Overflowed
select @Years = case when @monthOverflow < 0 then @years-1 else @years end
select @months = datediff(month,@Birthdate,@AsOnDate) - (@years * 12)
--as we do for month overflow criteria for days and hours
--& minutes logic will followed same way
declare @LastdayOfMonth int
select @LastdayOfMonth = datepart(d,DATEADD
(s,-1,DATEADD(mm, DATEDIFF(m,0,@AsOnDate)+1,0)))
select @days = case when @monthOverflow<0 and
DAY(@Birthdate)> DAY(@AsOnDate)
then @LastdayOfMonth +
(datepart(d,@AsOnDate) - datepart(d,@Birthdate) ) - 1
else datepart(d,@AsOnDate) - datepart(d,@Birthdate) end
declare @hoursOverflow int
select @hoursOverflow = case when datepart(hh,@AsOnDate) -
datepart(hh,@Birthdate) <0 then -1 else 1 end
select @hours = case when @hoursOverflow<0 then 24 +
datepart(hh,@AsOnDate) - datepart(hh,@Birthdate)
else datepart(hh,@AsOnDate) - datepart(hh,@Birthdate) end
declare @minutesOverflow int
select @minutesOverflow = case when datepart(mi,@AsOnDate) -
datepart(mi,@Birthdate) <0 then -1 else 1 end
select @minutes = case when @hoursOverflow<0
then 60 - (datepart(mi,@AsOnDate) -
datepart(mi,@Birthdate)) else abs(datepart
(mi,@AsOnDate) - datepart(mi,@Birthdate)) end
select
@Months=case when @days < 0 or DAY(@Birthdate)> DAY(@AsOnDate) then @Months-1 else @Months end
Declare @lastdayAsOnDate int;
set @lastdayAsOnDate = datepart(d,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,@AsOnDate),0)));
Declare @lastdayBirthdate int;
set @lastdayBirthdate = datepart(d,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,@Birthdate)+1,0)));
if (@Days < 0)
(
select @Days = case when( @lastdayBirthdate > @lastdayAsOnDate) then
@lastdayBirthdate + @Days
else
@lastdayAsOnDate + @Days
end
)
print convert(varchar,@years) + ' year(s), ' +
convert(varchar,@months) + ' month(s), ' +
convert(varchar,@days) + ' day(s), ' +
convert(varchar,@hours) + ':' +
convert(varchar,@minutes) + ' hour(s)'