If you are applying for Schengen Visa for the first time, processing your visa might take 3-4 weeks but if you have applied previously and this is your second time, it might take less time 3-5 working days. If you want to travel during Eid Holiday, you must call the guys at the greek embassy at the earliest possible and ask about the processing time; meanwhile you have to start collecting the required documents as stated above by nishu2310.