Yes, made in January.
Unlike the US & most other countries who just kept numbering rifles - ending up with serial numbers like 4, 397,456 the Germans ran a 4 dig series and then repeated it using a different letter of the alphabet till they ran out of letters. They then began at "a" again only with double letters - 456aa. They started over with 1 in January of each year.
Thus it is possible (But not likely) to own 12 different rifles made at Mauser Oberndorf with the same ser nr. and 12 different years dates. In this instance you would also have them spread thru 3 different factory codes - 42, S/42, byf - over the years.
Sarge