All Dana 60 differentials are also marked with a date code which are found on both housing, inboard of the BoM number, and on the side of the cylindrical part of the differential. Formatted "MM DD Y", the date code always represents the year as a single digit, except on differentials which can be two digits. Housing date codes are followed by a letter (A, B, or C) which may indicate the work shift or factory line. Some differential stampings also show this letter suffix. Zeros are not used in month and day codes. Wide variation in spacing of the components of the date code is seen, and it is not unheard of to see two date codes stamped into a housing, one above the other. These two date codes are usually within a few weeks of one another.