unable to update iphoto - says not available at this time. Try again. It has been showing this message for the last 3 days.

Apple stopped the development of iPhoto, and updating using the Updates tab does not work right now.

Don't try to update from the Updates tab at the App Store, move the incompatible iPhoto application from the Applications folder to the Trash (don't empty the Trash!), then try to update by reinstalling the iPhoto application from the Purchases tab of the App Store.

See Barney's User Tip for details:

Can't Update iPhoto because it is not available in the App Store

Same situation.

Based on léonie's reply, I moved iPhoto to Trash. Went back to Software Update where the iPhone update was listed, clicked Update and iPhoto update vanished, It no longer bugs me to update now. Will delete iPhoto in trash now and be done with it.

Go to the App Store and check out the Purchases List. If iPhoto is there then it will be v9.6.1

If it is there, then drag your existing iPhoto app (not the library, just the app) to the trash

Install the App from the App Store.

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Sometimes iPhoto is not visible on the Purchases List. it may be hidden. See this article for details on how to unhide it.

http://support.apple.com/kb/HT4928

One question often asked: Will I lose my Photos if I reinstall?

iPhoto the application and the iPhoto Library are two different parts of the iPhoto programme. So, reinstalling the app should not affect the Library. BUT you should always have a back up before doing this kind of work. Always.