แม่แบบ:Certification Table Entry/Sales/MexicanPeriod/doc

This helper template calculates periods for Mexican certifications, as stated in AMPROFON

It returns:

Until December 31, 1998	Until December 31, 1999	Until June 30, 2003	Until December 31, 2007	Until June 30, 2009	From July 1, 2009
1	2	3	4	5	6

Returns 0 if the data provided is not sufficient.