"Public holiday" means the first day of January (New Year's Day), third Monday of January (Martin Luther King's Birthday), third Monday of February (President's Day), last Monday of May (Memorial Day), fourth day of July (Independence Day), first Monday of September (Labor Day), eleventh day of November (Veteran's Day), fourth Thursday of November (Thanksgiving Day), the day immediately following Thanksgiving Day, and the twenty-fifth day of December (Christmas). (Ord. 93-63 § 1, 1993: Ord. 2735 § 2 (part), 1983).