What do you mean by "employment letter"? If it is a letter (not the appointment letter) from your employer verifying your employment, then it will be advisable to get a current one.
This is employment verification letter. It was given to me on my request of Employment verification Support for h1B samping. But I got my interview of date in July end. thus it is one month difference.
If it is the appointment letter, then it should be okay. But it is always a good idea to have a recent employment letter as a proof of continuing employment. Also don't forget to get recent paystubs with you.
Hope this helps.
Pay Stubs are only till the date I was in USA, after that I wasnt paid anything so no pay stub. Will it give some problem. I am working on hourly basis.