diff options
Diffstat (limited to 'src/isodate/duration.py')
| -rw-r--r-- | src/isodate/duration.py | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/isodate/duration.py b/src/isodate/duration.py index fa501cd..0d5e0fa 100644 --- a/src/isodate/duration.py +++ b/src/isodate/duration.py @@ -140,6 +140,8 @@ class Duration(object): newduration.tdelta = self.tdelta + other.tdelta return newduration if isinstance(other, (date, datetime)): + if (not( float(self.years).is_integer() and float(self.months).is_integer())): + raise ValueError('fractional years or months not supported for date calculations') newmonth = other.month + self.months carry, newmonth = fquotmod(newmonth, 1, 13) newyear = other.year + self.years + carry @@ -162,6 +164,8 @@ class Duration(object): newduration.tdelta = self.tdelta + other return newduration if isinstance(other, (date, datetime)): + if (not( float(self.years).is_integer() and float(self.months).is_integer())): + raise ValueError('fractional years or months not supported for date calculations') newmonth = other.month + self.months carry, newmonth = fquotmod(newmonth, 1, 13) newyear = other.year + self.years + carry @@ -199,6 +203,8 @@ class Duration(object): ''' #print '__rsub__:', self, other if isinstance(other, (date, datetime)): + if (not( float(self.years).is_integer() and float(self.months).is_integer())): + raise ValueError('fractional years or months not supported for date calculations') newmonth = other.month - self.months carry, newmonth = fquotmod(newmonth, 1, 13) newyear = other.year - self.years + carry |