The 30/360 day count can be calculated according to US, European, or
Italian conventions.
US (NASD) convention: if the starting date is the 31st of a
month, it becomes equal to the 30th of the same month.
If the ending date is the 31st of a month and the starting
date is earlier than the 30th of a month, the ending date
becomes equal to the 1st of the next month, otherwise the
ending date becomes equal to the 30th of the same month.
Also known as "30/360", "360/360", or "Bond Basis"
European convention: starting dates or ending dates that
occur on the 31st of a month become equal to the 30th of the
same month.
Also known as "30E/360", or "Eurobond Basis"
Italian convention: starting dates or ending dates that
occur on February and are grater than 27 become equal to 30
for computational sake.
30/360 day count convention
The 30/360 day count can be calculated according to US, European, or Italian conventions.
US (NASD) convention: if the starting date is the 31st of a month, it becomes equal to the 30th of the same month. If the ending date is the 31st of a month and the starting date is earlier than the 30th of a month, the ending date becomes equal to the 1st of the next month, otherwise the ending date becomes equal to the 30th of the same month. Also known as "30/360", "360/360", or "Bond Basis"
European convention: starting dates or ending dates that occur on the 31st of a month become equal to the 30th of the same month. Also known as "30E/360", or "Eurobond Basis"
Italian convention: starting dates or ending dates that occur on February and are grater than 27 become equal to 30 for computational sake.