New Year Plenary Indulgence

Via Fr Finegan:

A plenary indulgence is granted to the faithful under the usual conditions who devoutly assist at the singing or recition of:
The Te Deum on the lst day of the year to give thanks to God for benefits received during the past year.
The Veni Creator on 1 January to implore divine help during the coming year.

His post on Plenary Indulgences is also worth a read.