On this page the Time Step(s) to extract data from is specified as well as which projection system to use. The possible systems are those specified in the utm.dat file
Beware that there will be generated one output file for each selected Time Step. Each file will be postfixed with the Time Step number, e.g. having specified the output file C:\output.asc and selected time step 1 and 112 will cause the generation of the two output files C:\output001.asc and C:\output112.asc.