The Last Check on Host Details page is a last chek-host-alive check for that host. It doesn’t have any connection with regular service checks. Host check (check-host-alive) is executed only when all services fail (read, have Critical states) and when there is no Last Check information (like in the case you’ve moved retention.dat file and every host was in Pending state).
So, don’t get confused with the Last Check info on host’s, those are executed only in special conditions, and not on a regular basis. Services are checked on a regular basis.
This is cut/paste from official 2.0 version documentation, under Host definition
nagios.sourceforge.net/docs/2_0/ … .html#host
check_interval: NOTE: Do NOT enable regularly scheduled checks of a host unless you absolutely need to! Host checks are already performed on-demand when necessary, so there are few times when regularly scheduled checks would be needed. Regularly scheduled host checks can negatively impact performance - see the performance tuning tips for more information. This directive is used to define the number of “time units” between regularly scheduled checks of the host. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. More information on this value can be found in the check scheduling documentation.