Inconsistent

I’m trying to do a search of strings with a DATE Field in the first column, but in my case, the log file i’m searching is a mix of information/logging with and without the timestamp as first field.. My search is succesful only if the last lines contain the timestamp, otherwise it gives me this error

Error parsing time at /usr/lib64/perl5/vendor_perl/5.8.8/x86_64-linux-thread-multi/Time/Piece.pm line 465.