The employee can resign at any time by giving a written notice. Normally 1 month. There are bad and good employers in any part of the world and Qatar is not an exception. Normally employers are accommodating from workers coming from the first world countries (US, UK, etc.). There are employers that give NOC (NO Objection Certificate) and or release to their resigning employees. This will allow them to find employment elsewhere in Qatar. You can discuss this issue to your employer before coming to Qatar. If you need anything else, PM me your email and I will be glad to help you with other issues. Cheers