Custom CDR, time

How to make Asterisk write date/time on failed (busy, no answer, etc) calls? Now it looks like this:

SIP/alice-00003c60 78124552653 SIP/bob-00003c61 55119010578 2012-09-24 21:00:34 60 ANSWERED
SIP/alice-00003c64 73833630892 SIP/bob-00003c65 55123295822 2012-09-24 21:53:32 42 ANSWERED
SIP/alice-00003c66 73472903333 SIP/bob-00003c67 552763 0 NO ANSWER
SIP/alice-00003c68 73472903333 SIP/bob-00003c69 552794 0 NO ANSWER
SIP/alice-00003c6a 73522222853 SIP/bob-00003c6b 55097248167 0 BUSY
SIP/alice-00003c6c 73472903333 SIP/bob-00003c6d 5527 0 NO ANSWER
SIP/alice-00003c6e 78312157188 SIP/bob-00003c6f 55101293649 2012-09-24 23:00:27 14 ANSWERED
SIP/alice-00003c70 78432113657 SIP/bob-00003c71 55172266625 0 BUSY
SIP/alice-00003c72 78124544863 SIP/bob-00003c73 55110253182 0 BUSY

Use the start time or end time, rather than the answered time.

Thanks!