Barclays Bank is a type of British multinational banking company.
It was established in the year 1690.
It’s headquarter is located in London, England, United Kingdom.
Its products are:
Retail banking
Commercial banking
Investment banking
Investment management

As you have asked about the branch opening timings of Barclays Bank Twickenham branch, check below for the details
Opening times

Monday 09:30 - 16:30
Tuesday 09:30 - 16:30
Wednesday 09:30 - 16:30
Thursday 09:30 - 16:30
Friday 09:30 - 16:30
Saturday 09:30 - 14.00
Sunday Closed

It offers following facilities:

External ATM with audio
Account verification service
DDA interview room
Mortage advisor

Contact:
2 York Street
Twickenham
Middlesex
TW1 3LE
Telephone: 0345 734 5345 (central customer services)
You can also find about it from the bank website.
Go to Barclays bank website.
Scroll down and click on Find a branch at bottom of screen, the page open look like


Here enter the details and you will get the result.