Travel to Canada while on US tourist visa

[maninrace]

My parents got 10 year multiple entry visitor visa to USA. They also want to visit Canada to see my brother. They are taking round trip tickets from India to US. Most likely they would get the Duration of Stay of around 6 months on the port of entry to USA.

So, can they travel to Canada for few days with in those 6 months and come back to USA??? I assume Multiple entry means they can enter back to US but how about Duration of Stay, will that change once they come back from Canada??

[Murali]

This is what the visa/immigration authorities says

B1 and B2 visas are usually issued for a term of 10 years. Each visit may last up to six months, although some categories of visitors may apply to extend their visit for an additional 6 months. During your visit to the U.S., you may visit Canada, Mexico, or the Caribbean islands (not Cuba)for up to 30 days and re-enter the U.S. as long as you re-enter within the period noted on the Form I - 94 which you received when you first entered.
For instance, if you come to the U.S. on July 10, 2005 on a B2 Visitor Visa, you may go to Canada and/or Mexico on or after November 10, and reenter the U.S. any time up until December 10. But because the six month period is up on December 10, 2005, you will also have to depart from the U.S. on that same day to avoid being an "overstay" (unless you applied for an extension of stay.)

official website :
http://help.cbp.gov/cgi-bin/customs.cfg/php/enduser/std_adp.php?p_faqid=751

[maninrace]

Thank you Murali ! Your response is really helpful. :)