Many annotation tracks are updated very frequently. For instance RefSeq is updated almost daily by NCBI.

We do not have the ressources to update our files daily. You can get the latest version of most files using the DAS server accessible through GenPlay,

For most purpose, you do not need the latest version since you need some stability to do your analysis. We provide here files that are somewhat out of dates but still very useful

The name of the files indicate the name of the track, followed by the date when the file was downloaded from UCSC or from some other source, and in parenthesis the assembly.