Units.
reftime
The reference date-time of reference time units.
See also
calendar, isreftime, units
calendar
isreftime
units
Examples:
>>> Units('days since 1900-1-1').reftime <Datetime: 1900-01-01 00:00:00> >>> str(Units('days since 1900-1-1 03:00').reftime) '1900-01-01 03:00:00'
TODO