source date. Thus wxDateSpan::Months(1) is not equal to wxDateSpan::Days(30),
because they don't give the same date when added to 1 Feb. But
wxDateSpan::Days(14) is equal to wxDateSpan::Weeks(2)
source date. Thus wxDateSpan::Months(1) is not equal to wxDateSpan::Days(30),
because they don't give the same date when added to 1 Feb. But
wxDateSpan::Days(14) is equal to wxDateSpan::Weeks(2)