Dear Rabbi Simon,
I’m supposed to be working on Sunday the 9th of Av. It is easy work to fast on, and I will be on my own in the office. Is it allowed to work on that day?
Working on 9 Av is not highly recommended, but in order to avoid financial loss (for example), it is allowed. It is best to work only after midday, if possible. Halakhic midday on 10 August this year is 1:06pm (due to BST). Also, it is preferable not to greet people in the normal way, and not to sit on a regular chair, until after midday. For these reasons it would be preferable to either switch with a colleague on that day, or work the afternoon shift, if you can.
Have an easy fast,
rabbi rashi simon