Answer: not long at all. And MPs have no obligation to attend any sittings unless they are whipped to do so.

Mondays 2.30-10.30pm

Tuesdays and Wednesdays 11.30am-7.30pm

Thursdays 9.30am-5.30pm

Sitting Fridays 9.30am-3pm
(There are only 13 “sitting Fridays” in this Parliament)

Commons Hansard: Sittings of the House

http://www.parliament.uk/about/faqs/house-of-commons-faqs/business-faq-page/

MPs (such as Neil Parish) who sit on committees have slightly more work, though his committee has no current scheduled meetings arranged:

http://www.parliament.uk/business/committees/committees-a-z/commons-select/environment-food-and-rural-affairs-committee/

If you want to see exactly what is happening day by day here is the daily diary of Parliamentary activities:

http://calendar.parliament.uk/

The website of the Conservative Middle East Council, of which Hugo Swire is Chairman, does not give details of its meetings:

https://cmec.org.uk/