You can use sp_addlanguage to install names for the days of the week and months of the year for languages that do not have Language Modules. With sp_addlanguage, you define:
A language name and (optionally) an alias for the name
A list of the full names of months and a list of abbreviations for the month names
A list of the full names of the days of the week
The date format for entering dates (such as month/day/year)
The number of the first day of the week
This example adds the information for Italian:
sp_addlanguage italian, italiano, "gennaio,febbraio,marzo,aprile,maggio,giugno,luglio,agosto,settembre,ottobre,novembre,dicembre", "genn,feb,mar,apr,mag,giu,lug,ago,sett,ott,nov,dic", "lunedi,martedi,mercoledi,giovedi,venerdi,sabato,domenica", dmy, 1
sp_addlanguage enforces strict data entry rules. The lists of month names, month abbreviations, and days of the week must be comma-separated lists with no spaces or line feeds (returns). Also, they must contain the correct number of elements (12 for month strings, 7 for day-of-the-week strings.)
Valid values for the date formats are: mdy, dmy, ymd, ydm, myd, and dym. The dmy value indicates that the dates are in day/month/year order. This format affects only data entry; to change output format, you must use the convert function.
