Vacation pay is calculated as a percentage of gross wages earned.
I understand that most legislation these days is designed to ensure that women who take pregnancy leave are not disadvantaged in any fashion. Under the Employment Standards Act, vacation is composed of two separate elements. The first is vacation time, which accrues through length of employment. You earn your entitlement to vacation pay based upon how long you have worked with your employer. There is no requirement that the employee be actively working during the period.