Visa expiry date doesn't determine length of stay: US
The authorised length of stay for international visitors in the United States is not determined by the expiration date on their B1/B2 visitor visa, but rather by the immigration officer present at the port of entry upon arrival
ATT Desk Report 
The United States Embassy in Dhaka on Saturday clarified that the authorised length of stay for international visitors in the United States is not determined by the expiration date on their B1/B2 visitor visa, but rather by the immigration officer present at the port of entry upon arrival, says a Facebook post of the embassy.
According to the post on the embassy's verified Facebook page, travellers have been asked to consult the "admit until date" recorded on their Form I-94—the official arrival and departure record maintained by US Customs and Border Protection (CBP)—to determine the precise period they are permitted to remain in the country.
The I-94 record can be accessed electronically through the CBP's official portal at i94.cbp.dhs.gov.
A B1/B2 visa grants the holder eligibility to apply for admission into the United States but does not itself confer the right to remain in the country for its full duration. The actual period of admission is a separate determination made at the border by an immigration officer and may differ from the visa's validity period.
