I say No. 1 below. Do you? If we use commas (as in the second sentence), we won't know which Saturday or Sunday.

He will work Saturday the 14th till Sunday the 22nd.

He will work Saturday, the 14th, until Sunday, the 22nd.


He will work Saturday, December 14th, till Sunday, December 22nd. Correct?
Too many commas in your succeeding examples: the reader will never be able to finish the sentence. Use #1. In #3, at least delete the comma after '14th'! Commas are valuable; don't abuse them.
Students: We have free audio pronunciation exercises.
Thanks, MM.
Thanks again. So I believe you may eliminate the comma after the year in a construction like this.

July 7th, 2010 was a milestone in her life.

July 7th, 2010, was a milestone in her life.

Some style manuals say 'yes'; others say 'no'. I see no need for the 2nd comma. Why not invert?-- 7 July 2010 was a milestone.
Teachers: We supply a list of EFL job vacancies

Although style manuals encourage the inclusion of the comma, to me it is redundant and unnecessary.
I will eliminate commas, then, in adjectival references as well. I'm sure you'd agree (I think).

The May 5, 2005 issue was a big seller.
NOT: The The May 5, 2005, issue was a big seller.

The Little Rock, Arkanasas father was arrested for killing his wife.
NOT: The Little Rock, Arkanasas, father was arrested for killing his wife.