select shortmonths from master.dbo.syslanguages where name = 'us_english'

select distinct number, datename(month, dateadd(month, number, -1)) as Month,
    left(datename(month, dateadd(month, number, -1)), 3) as ShortMonth
from master.dbo.spt_values where number between 1 and 12

/*
shortmonths                                            
-------------------------------------------------------
Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec

number      Month                          ShortMonth 
----------- ------------------------------ ---------- 
1           January                        Jan
2           February                       Feb
3           March                          Mar
4           April                          Apr
5           May                            May
6           June                           Jun
7           July                           Jul
8           August                         Aug
9           September                      Sep
10          October                        Oct
11          November                       Nov
12          December                       Dec
*/