Date envionement variable in windows

I want to create log files for a process I am automating in WinXP. Included the log file name,1 I want to have the date when the scheduled task ran. I have tried using the %DATE% environment variable without any success. The line which does not work is below.

defrag C:\ /v >"C:\Program Files\Disk Defragmenter\Logs\Defrag_log_%DATE%.txt"

Does any one know why the current date will not print out? Do I need a delimiter around %DATE% or something? Thanks.

I haven't written a single line of script or code in years but I think your line should be :

defrag C:\ /v >"C:\Program Files\Disk Defragmenter\Logs\Defrag_log_"%DATE%".txt"

Because if you put your variable inside the text delimiters, it will be treated as text and won;t be recognized as a variable.

Please let me know if my suggestion works.

No that does not work either. I do not know if double quote are the delimiter. Here is the error message.

Two or more parameters that could be a volume exist.
There can be only one drive letter or volume mount point parameter.

Any other suggestions?