Convert month name to month number in SQL Server

In T-SQL what is the best way to convert a month name into a number?

E.g:

'January' -> 1
'February' -> 2
'March' -> 3

Etc.

Are there any built in functions that can do this?

How about this?

select DATEPART(MM,'january 01 2011') -- returns 1
select DATEPART(MM,'march 01 2011')  -- returns 3
select DATEPART(MM,'august 01 2011') -- returns 8

How about this:

SELECT MONTH('March' + ' 1 2014') 

Would return 3.

Its quit simple, Take the first 3 digits of the month name and use this formula.

Select charindex('DEC','JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC')/4+1

You can create a function and then refer to it in the select statement. The function may look similar to this:

if OBJECT_ID('fn_month_name_to_number', 'IF') is not null
drop function fn_month_name_to_number
go
create function fn_month_name_to_number (@monthname varchar(25))
returns int as
begin
declare @monthno as int;
select @monthno =
case @monthname
when 'January' then 1
when 'February' then 2
when 'March' then 3
when 'April' then 4
when 'May' then 5
when 'June' then 6
when 'July' then 7
when 'August' then 8
when 'September' then 9
when 'October' then 10
when 'November' then 11
when 'December' then 12
end
return @monthno
end

Then you can query it.

select fn_month_name_to_number ('February') as month_no

This query will return 2 as month number. You can pass values from a column as parameters to the function.

select fn_month_name_to_number (*columnname*) as month_no from *tablename*

Have a good day!