After El Capitan, Calendar is slow, jerky in 'week' view.

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step is to determine whether the problem is localized to your user account.

Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.

Please take this step regardless of the results of Step 1.

Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem?

After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.

May I jump in to this thread? LMK if you'd like me to do something different as I'm not a usual poster in this forum.

Step 1 -- followed instructions and delay doesn't exist in Week Calendar mode.

For Step 2, how do I know if I"m using FileVault?

no longer a question... proceeding with Step 2

Back up all data. If you have iCloud calendars, archive them by following the instructions on this page under the heading "Downloading a calendar from iCloud.com." All you need is a web browser, not the Calendar application. Do the same with any other network calendars you have, if possible.

Before taking each of these steps, quit (force quit if necessary) the application. After taking the step, relaunch and test. When the problem is resolved (or when you complete Step 3 without resolving it), stop and close the Library folder.

Step 1

Hold down the option key and select

Go ▹ Library

from the Finder menu bar. From the folder that opens, move these items (some may not exist) to the Trash, leaving the Library folder open:

Calendars/Calendar Cache

Calendars/Calendar Cache-shm

Calendars/Calendar Cache-wal

Step 2

Move these files from the Library folder to the Desktop (again, some may not exist):

Containers/com.apple.CalendarAgent (and any others with a name beginning in "com.apple.Calendar")

Containers/com.apple.iCal (and any others with a name beginning in "com.apple.iCal")

Preferences/com.apple.CalendarAgent.plist

Preferences/com.apple.iCal.plist

If the problem is resolved, you may be able to put back some of the items you moved in this step, relaunching and testing after each one. Eventually you may find the one that caused the problem; delete it. Recreate your settings as necessary.

If the problem still isn't solved, put back each of the items you moved in this step, overwriting the one that may have been created in its place. You don't have to put back the files you moved in Step 1.

Step 3

Move this folder to the Desktop:

Calendars

Note: you're not moving the Calendars application; you're moving a folder named "Calendars". If there's no change, put the folder back where it was.

If the problem is resolved after you move the Calendars folder, the event database is corrupt. You have these choices:

Restore the folder from a Time Machine snapshot or other backup that predates the corruption.

Use a third-party application such as Calendar Cleaner to try to repair the database.

For network calendar accounts, such as iCloud, all you should need to do is re-enter them in the preferences. For subscribed calendars, you only need to re-subscribe.

scrolling normal now for me as well.

Thanks for the help, both of you.