Following public consultation earlier this year, Shropshire Council has announced the new opening hours will start from October 3.
Meanwhile, Shawbury's library will close today and be replaced with a mobile service.
The mobile service will run in the village hall car park, starting on October 4. It will run on Tuesdays, from 11.30am to 12.30pm, and on Fridays, from 9.30am to 10.30am.
Shawbury Parish Council said it could not afford to keep the village library open as it would have cost it about half of its budget.
Across 11 of the county's libraries the council will cut a total of 57 opening hours.
Councillor Stuart West, Shropshire Council's cabinet member responsible for libraries said that the move would ensure that libraries could remain open.
He said: "They are mild savings not really affecting libraries to a great extent.
"We are keeping libraries open which is important and I think in general the response from the public has enabled us to put in operation a scheme for each individual library.
"Originally it was proposed to have a 68 hour reduction, through the consultation it has been reduced to 57 hours across 11 libraries.
"It is very important to recognise that library services are very important and it is important we do keep them open. I think what we have come up with in the review of opening hours is sensible."
A summary states that in general the revised hours will mean a lunchtime closure where feedback justifies it, and that libraries will open from 9.30am.
In Market Drayton, the town's library will open from 9.30am-6pm on Mondays, 9.30am-5pm on Tuesdays, Wednesdays and Fridays and 9.30am-1pm on Saturdays, but it will be closed on Thursdays.
In the south of the county, the opening times at Much Wenlock Library will be 9.30am-1pm then 2pm-5pm on a Tuesday and Thursday and 9.30am-1pm on a Saturday, but closed on Mondays, Wednesdays and Fridays.
In Shrewsbury, the library will be open from 9.30am-5pm from Monday to Friday with longer opening hours on a Thursday until 7pm. and 9.30am – 4pm on a Saturday.
Hours have also changed in Bridgnorth, Gobowen, Oswestry and Whitchurch.
The changes come just weeks after Telford & Wrekin Council revealed it had revised plans to close some of its own libraries.
Three of the six under-threat libraries in the county – Donnington, Dawley and Stirchley – will now be run by town or parish councils.
A fourth library in Hadley will be run by Hadley Learning Community, supported by Hadley & Leegomery Parish Council. Telford & Wrekin Council will also continue to run and operate Newport and Madeley Library with some changes to opening hours.
For more opening times and information on Shropshire's libraries, visit new.shropshire.gov.uk/libraries