With passenger numbers down and the likelihood that some staff will be self-isolating, the company says it wants customers to have reliable bus times.
By taking this action, the management hopes to create a timetable robust enough to withstand any further disruption.
The bus cleaning regime has also been intensified with all poles, hand rails, seats and other key areas of its vehicles disinfected regularly.
Details of the revised timetable are available on the Yellow Buses’ website as well as on its app and at most bus stops.
Managing director David Squire said: “We will continue to provide a safe, reliable service for those travelling to work and making other journeys.
“By making these changes now we are hope to ensure a sustainable service as the pandemic develops.
“The situation with Covid-19 continues to change by the hour and we will keep customers up to date with the latest information through our usual channels.
“Our staff have reacted brilliantly to the situation and are pulling together in order to keep the buses running.”
School services remain unaffected by the changes, but there are certain other timetable tweaks beyond the regular Saturday service.
For example, there will be additional trips on the 737 service to the business park by Bournemouth Airport and on the 21 Burton service.
Service 8, which operates Monday to Friday, will now only operate three return journeys at the peak times.
Service 21, which operates from Monday to Friday, will be unchanged.
Routes N1 and N5 will not operate until further notice.
There will also be some changes to the open top summer services and these will be announced later.