(PHP 5 >= 5.3.0)
Represents a date interval.
A date interval stores either a fixed amount of time (in years, months, days, hours etc) or a relative time string in the format that DateTime's constructor supports.
Number of years.
Number of months.
Number of days.
Number of hours.
Number of minutes.
Number of seconds.
Is 1 if the interval represents a negative time period and 0 otherwise. See DateInterval::format().
If the DateInterval object was created by
DateTime::diff(), then this is the total number of
days between the start and end dates. Otherwise,
days will be
Before PHP 5.4.20/5.5.4 instead of
FALSE you will receive -99999 upon
accessing the property.