Timeperiods problem

Hi all,
I have a problem with timeperiods on nagios. I’d like to define a particular timeperiod for receiving host and service notification on an alternative email address.
Here is my definition:

define timeperiod{
timeperiod_name timeperiod1
alias Example

friday 16:45-24:00
saturday 14:00-24:00
sunday 00:00-24:00

january 1 00:00-24:00
may 1 00:00-24:00

}

At 16:30 of friday 19/12 I get notifications.
If I comment the line (may 1 00:00-24:00) I get only notification on the right time/days. What am I doing wrong ?

Thanks in advance,
Stefano