Vacation is contractual and detailed in section 11 - we just happen to have that contract in our downloads section:

11-A
Newly employed pilots will accrue one and one-sixth (1 1/6)
days of vacation for each full calendar month of continuous
employment with the Company during the remainder of the
vacation year after date of their initial employment, provided that
the first vacation for pilots initially employed on or after May 1 of
any year will not be due or payable except between May 1 and
April 30 of the next succeeding vacation year.

11-B
Yearly vacation accrual

11-B-1-a After the provisions of Paragraph 11-A of this
Section have been complied with, pilots shall receive
sixteen (16) days vacation each year provided
employment has been continuous. Commencing in the
vacation year following the completion of continuous
service shown below, pilots will receive vacation in the
following schedule:


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Note: anyone wanting to submit a contract please PM me.