Rolex chief executive Jean-Frederique Dufour has informed colleagues that plants will close for 10 days from 5pm today.
It is hoped they will reopen on March 27, but the statement does not rule out extending the closure.
“We face a very serious situation,” he wrote in a letter to employees today.
The decision was made to protect staff and their families and also to help limit the spread of Coronavirus, the letter, written in French, continues.
Three plants in Geneva, Bienne and Cressier are all affected.
Rolex keeps details of its production as a closely guarded secret, but there is an industry consensus that it makes around 1 million watches per year and aims to increase that total by around 6% per annum.
A 10 day shut down could mean a drop in production this year of 2.7%, although Rolex may catch up during the summer when factories tend to slow down in normal times.
As of this morning, March 17, there has been no official announcement from Swatch Group, Richemont or LVMH on their corporate websites.
Full translated text of the letter from Mr Dufour
As I have previously said, we are facting a very serious situation. With the objective to protect you, your families and those close to you, but also to limit risks of propagation and the spread of Coronavirus, we have decided to close our sites of production in Geneva, Bienne and Cressier from Monday 17th of March [sic] until Friday 27th of March.
This date is subject to change based on the evolution epidemic. Certain services will stay open to answer imperative operational questions.
We will send more details on the subject. From here we ask you to respect the letter, and the measures of confinement specified by the authorities in Switzerland and in France.
I am certain this bad passage of time will pass and we will keep our composure and contribute to stabilising the situation and work in the best possible way.
Thank you for accepting the instructions of your managers to ensure this closure in good conditions. I hope it all ends, good luck for all the days to come and take good care of yourself.