Days360 Returns Incorrect Results Sometimes

Hi all,

Using Excel 2013.

Sometime Days360 is retuning incorrect results
I tried both EU and US Methods - same results

Data
Begin............End.........Days360
11/1/2011..4/30/2012....179......Incorrect should be 180
11/1/2010..10/31/2011..360......Correct
2/1/2012....7/31/2012....180.....Correct
1/1/2012....6/30/2012....179.....Incorrect

Any idea what is going on?

thx
w

Don't use days360
If you use this a year has 360 days instead of 365 (366)
Beter use datedif or just 'end' minus 'begin' date

Thanks,

I do need 12 months of 30 days each = 360 days

with end - begin: 11/1/2011..4/30/2012....181
with Days360: 11/1/2011..4/30/2012....179

We've surrounded the answer I'm looking for (180)

thx
w