title: Xcode Codesign error: timestamps differ
body: <p>My attempts at signing my application within XCode are failing with an error "Code signing failed: check that the identity you selected is valid".
  Since my certificates all check out as valid I tried using the codesign utility in Terminal.
  When I run it with these parameters:
  codesign --force --deep  -s  
  I get this cryptic error:
  timestamps differ by 230 seconds - check your system clock</p>
  
  <p>I have research this error in the documentation and all over the web and found nothing.</p>
  
  <p>Any ideas ?
  Thank you.</p>
  
  <p>Update - a few days later: I was able to dispense with this problem by getting fresh certificates and signing identity and doing a "Clean Build Folder" (hold the option key down when choosing Clean Build).</p>