1. On RC page select the "Time period to search" option to be different from what was saved in Preferences-Recent changes.
2. The Preferences-Recent changes "Days to show in recent changes" option will be updated to the user selected value.
3. Select one of the hours options on RC page - the Preferences-Recent changes "Days to show in recent changes" option won't be updated.
Note 1: Currently it's not even possible to save the value between 0 and 1 in Preferences-Recent changes "Days to show in recent changes" option. The warning says: "Value must be greater than or equal to 1" which does not cover all valid values for this option.
Note 2: The Watchlist behaves correctly - any user-selected option for "Time period (in days) to search" " will be reflected in Preferences-Recent changes "Days to show in recent changes" option.