Q: I tried installing mavericks and i always get "This copy of the Install OS X Mavericks application can't be verified. It may have been corrupted or tampered with during downloading."

Also just to double check, Is this the code everyone used to make their bootable/installable usb drive for Mavericks from terminal?

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction

Please let me know

Also just to double check, Is this the code everyone used to make their bootable/installable usb drive for Mavericks from terminal?

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction

Please let me know

plochner, (and everyone who is still having this issue. Especially if you are on Snow Leopard OS X 10.6 give this post a try)

I finally got a hold of a copy of Snow Leopard today after re-trying 10-20 times with the same bootable usb with Maverikcs (correction: I re made the usb with another download of Mavericks and used DiskMaker X to make the usb. Still didn't work with same verfied issue).

I installed (clean) Snow Leopard on my Macbook and got into my Macbook once again. Updated to download App Store and downloaded Mavericks. But this time I used Ethernet LAN cable instead of wifi). I tried making the bootable usb but I kept getting the same error in terminal

error: Failed to start erase of disk due to error (-9999, 0)

I googled a bit and found this post

http://www.oddzuki.com/bootable-os-x-mavericks-usb-flash-drive-9999-error-fix/

Apprently it is a known issue on 10.6 with making the bootable USB. Following these steps helped me make a successful bootable USB.

Restarting my Macbook with bootable USB let me get in to the Mavericks install mode. I was excited that it seemed promising but I was a little worried becuase I wasns't sure how I was going to erase my HDD first before installing it. Playing around with the menu bar a little bit will help you find Disk Utility to format your HDD and then get back to installing Mavericks. Mine is working now!!!!!!!

Thanks everyone with the post and help. Although the date change wasn't a fix for me, this thread gave me hope and increase in tenacity to get it done. Thank you plochner for responding to my posts and suggesting putting Snow Leopard back on to work on it. I was feeling so hopeless and helpless when I realized that the installable USB wasn't going to work for me and I had no OS on the Macbook.

PERFECT. That is precisely what the problem was. You saved me a bunch of time, thank you so much Bill.

Downloading Mavericks via wireless is a FAIL!

After downloading Mavericks 4 times over Verizon wireless and continuously getting "This copy of the Install OS X Mavericks application can't be verified...." then trying it once on DSL and getting a perfect download/install, I think it's clear that apple store's data validation over wireless *****.

I've not had any trouble with any other application from other sources using the same wireless.

If you are using a wireless connection to get Mavericks and it keeps breaking, I would suggest trying a nailed up internet connection instead.

THANK YOU!! This worked wonderfully for me!
Just a note to those reading this....you do NOT need to type "sudo" into the Terminal. I just typed date. The format is MONTH&DAY&HOUR&MINUTE&YEAR so March 5th 2014 at 4.15pm is date 0305161520014. Very happy it worked for me.

After trying everything suggested here the only thing that worked for me was emptying the trash.

Following Jonathan Mohar's advice worked a treat for me as well :-)

http://blog.mconserv.net/2013/10/install-os-x-mavericks-application-cant.html

Changing the date to current date in terminal worked for me.

Bill, thank-you, my sanity was starting to slip towards oblivion.

I installed a new hard drive and in that process had disconnected my battery which reset the clock. After updating the system clock to the correct time, the install disk worked fine.

I changed the date in terminal and it worked for me too!

I did both the date fix AND connected the laptop to my router via ethernet. Not sure if both were necessary but it did work.

I fixed the time but still always get the error. Despite the time being correct, the timezone isn't. Anybody know if this would still be the problem? If so do you know how to change the timezone from within the installer usb?

Had the same issue and the date change thru terminal fixed it for me.  Thank you!

This did the trick for me! Thanks!!!!