Per the "Contract" 14.A.6: emphasis added by me,

The Company may require a pilot to provide the System Chief Pilot’s designee with a written statement from the pilot's physician explaining his inability to perform his assigned duties because of illness or injury if:

1. The Company has a good faith, and objective reason to question a pilot’s use or attempted use of sick leave; or
2. The pilot's absence from duty occurred in conjunction with his vacation period or a "holiday." As used herein, "holiday" means Easter, Memorial Day, Independence Day, Labor Day, Thanksgiving, Christmas Eve, Christmas, New Years Eve or New Years Day; or
3. The pilot has requested to utilize his disability sick account in accordance with Section 14.D.2.a.

I don't see - or just missed - the prior "near a holiday" suggestion.