Trigger to notify Lead Owner if the Lead Stage is not changed within 1 day from Lead Creation date

Trigger to notify Lead Owner if the Lead Stage is not changed within 1 day from Lead Creation date

Hi,

I'd like to create a trigger to notify Lead Owner if the Lead Stage is not changed from Open to Contacted within 1 day from Lead Creation date. This looks like a Time-based action but the problem is how can i check the lead stage before setting a Time-based alert?

Regards,
AMR