There is no single standard that works for every office. The frequency depends on the number of employees, the layout and how the rooms are used.
Start with occupancy
An office with many people present every day needs cleaning more often than a building that is partly used flexibly. Count visitors and meetings as well.
Differentiate between rooms
Washrooms, kitchenettes and entrance areas get dirty faster than archives or quiet workspaces. Setting a frequency per room keeps the plan efficient.
Schedule periodic work separately
Floor maintenance, window cleaning and deep cleaning do not belong in the daily round. Plan them periodically, for example quarterly or twice a year.
Evaluate and adjust
A cleaning plan is not fixed. If your team grows or the layout changes, discuss whether the frequency should be adjusted.