perl -e 'print $a=(localtime())[5]'
105
[download]

Update: Or, following BrowserUK:

perl -e 'print +(localtime())[5]'
105
[download]

Update: But not (in response to socketdave):

perl -e 'print (localtime())[5]'
syntax error at -e line 1, near ")["
Execution of -e aborted due to compilation errors.
[download]