Modules & VBA :: How To Input Alarm In Access Database

how to input alarm in my access database? I have data that should be insert over and over in 4 hours duration, when I put first data, I get local time and I need timer that could count 4 hours and after to make notification (massage) that the time for the Product of the database are over and need to input clean Product.

something like in first-->
ProductTime is column from Access Database
i=j=ProductTime;
for (i=0;i>= j+4hours, i++)
{
If(i=j+4h)
{
msgbox("ALARM- TIME is OVER");
}
}