Ping to port 13

[Chris Harvey]

I notice that on my firewall I get a lot of ICMP packet pings to my port 13 which /etc/services suggests is 'daytime'.   Is this something I should be concerned about? Should I DENY or REJECT all ICMP from 1-1024 or something like that??   Usually the log comments that the message was repeated three times, which I would think is normal behavior for ping, but I wanted to check with the 'experts'!   Chris