Test date failed

When i run commander.js tests on my computer, only one test failed with this error : 

   test.prompt.js ✖

/Users/despe_ki_roule/commander.js/node_modules/should/lib/should.js:125
      throw new AssertionError({
            ^
AssertionError: expected 1341301481000 to be an instance of Date
    at Object.<anonymous> (/Users/despe_ki_roule/commander.js/node_modules/should/lib/should.js:355:10)
    at /Users/despe_ki_roule/commander.js/test/test.prompt.js:36:27
    at parseDate (/Users/despe_ki_roule/commander.js/lib/commander.js:736:5)
    at EventEmitter.<anonymous> (/Users/despe_ki_roule/commander.js/lib/commander.js:756:5)
    at EventEmitter.g (events.js:156:14)
    at EventEmitter.emit (events.js:67:17)
    at EventEmitter.write (/Users/despe_ki_roule/commander.js/test/test.prompt.js:12:38)
    at /Users/despe_ki_roule/commander.js/test/test.prompt.js:84:11
    at EventEmitter.expect (/Users/despe_ki_roule/commander.js/test/test.prompt.js:21:3)
    at Object.<anonymous> (/Users/despe_ki_roule/commander.js/test/test.prompt.js:82:8)
make: *** [test] Error 1

This commit try to resolve this.