Depends who calls it a holiday and who pays you. By law there are no holidays, no sick time, no vacation pay -- it's how your company defines each item. A MSO hires the contractor - If work as an employee and your company defines Labor day as a holiday then you would follow their rules. The MSO isn't responsible nor are they your direct employer in regartds to holiday pay - your employer is or if your a 1099 single contractor - you work when work is available I would assume.
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