Microsoft Office Tutorials and References
In Depth Information
DATEDIF has been in Excel forever, but it was only documented in Ex-
cel 2000. Why doesn ’ t Microsoft reveal DATEDIF in Help? Probably
because of the strange anomaly when you try to calculate the gap
from the 31st of January to the 1st of March in a non-leap year.
The “ D ” version of DATEDIF reports this as 29 days. This is cor-
The “ M ” version of DATEDIF reports this as one full month. This
has to be correct because the dates span the entire month of Febru-
The “ MD ” version of DATEDIF reports this as a negative 2 days
in excess of a full month. See cell D9 in Figure 11.45 . This is simply
the downside of trying to express a measurement in months, when the
length of a month is not constant. Negative values for this version
of DATEDIF happen only when the end date is March 1 or March 2.