Following installation of OS 26.5.2 on my 27 inch Mac I have found that the Calendar no longer shows horizontal and vertical lines outlining the days. It only displays the actual appointments. How can I fix it?
iMac 27″
First, update to the current version of macOS, which is 26.6.
Keep your Mac up to date - Apple Support
In the macOS calendar app, that is not something that can be controlled by a setting. Quit and relaunch the app. If the issue remains, reboot your Mac and try again.
See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.
Start up your Mac in safe mode - Apple Support
First, update to the current version of macOS, which is 26.6.
Keep your Mac up to date - Apple Support
In the macOS calendar app, that is not something that can be controlled by a setting. Quit and relaunch the app. If the issue remains, reboot your Mac and try again.
See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.
Start up your Mac in safe mode - Apple Support
The Calendar app preferences, specifically the .plist file, must have become corrupted. Try this:
Ended up finding a solution from an old/closed inquiry from someone a few years ago. It is to go to System Settings/Accessibility, then go to Display contrast and then make sure it is lowered to "Normal" and not higher toward to all the way to "Maximum".
It worked! Thanks to whomever it was who found this and posted that awhile back.
The grid lines are there but are very very light. If you switch to dark mode you will see them. No clue why the option to make them much more visible is not there. TIP: try reducing the display contrast (under Accessibility, Display in system settings). It helps a lot.
digigate - you nailed it! Perfect solution. Lowering display contrast brought out the missing lines. Many thanks!
No impact. Still no grid lines on Calendar.
Calendar grid lines missing on Mac after OS 26.5.2
