Metro provides free Christmas Eve and New Year's Eve transport. Not all day mind you, read the specifics below.
"Specifically, no fare will be charged starting 9pm on Tuesday,
December 24 until 2am Wednesday, December 25 and starting 9pm on
Tuesday, December 31, 2013 until 2am on Wednesday, January 1, 2014. All
Metro Rail Line Stations with latched gates will be unlatched during
this time.
One-way fare is $1.50 for travel in one direction, on one line only.
A $5 Day Pass covers unlimited travel starting on date of purchase
until 3am the next morning.
Note: All Metro Rail lines and the Metro Orange Line will operate all night every 20 minutes on New Year's Eve."
source