[vagrant@localhost ~]$ cat /tmp/test
4014122102

[vagrant@localhost ~]$ date
Sun Dec 21 15:03:27 UTC 2014

sed -e 's|[0-9]{10}|date|g' /tmp/test

sed -e 's|[0-9]{10}|$date|g' /tmp/test

sed -e 's|[0-9]{10}|=date|g' /tmp/test

40141221

Sun Dec 21 15:00:51 UTC 2014

[vagrant@localhost ~]$ sed -e 's|[0-9]{10}|=strftime("%Y%m%d00")|g' /tmp/test
=strftime("%Y%m%d00")

[vagrant@localhost ~]$ sed -e 's|[0-9]{10}|$date|g' /tmp/test
date
$date
=date