The USCIS will send you a Notice of Action specifying the date that the change of status became effective. This will be the date of approval, not the date of filing.
Please click the link at the very bottom for additional information.
Carl Shusterman, Esq.
Former INS Trial Attorney (1976-82)
Board Certified Immigration Attorney (1986 - Present)
Schedule a Legal Consultation - Telephonic, Skype or In-Person
600 Wilshire Blvd., Suite 1550
Los Angeles, CA 90017
(213) 394-4554 x0
Web: www.shusterman.com (English)
(213) 394-4554 x0 Mr. Shusterman is a former INS Trial Attorney (1976-82) with over 35 years of immigration experience. His response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Shusterman's statement above does not create an attorney/client relationship.
From the date of approval, although if you file for change of status before the expiration of your existing status, your stay during the time it takes to immigration to adjudicate the application is deemed to be in lawful status.