Macro of reminder When Time in Particular cells orrurs

Hi,
Can someone please help on this.
I have daily excel to be mainteined in which client assigns me tasks and i need to approach them back withing exact 15minutes of task being assigned.
But because of multimple tasks I forget to check it and many a times it gets overdue.
Can you please assist me with VBA Codes which can help to send a reminder whenever my tasktime equals to current time.
A B C
Tasks At To Be Done By
log1 6:00 AM 6:15 AM want reminder whenever current time
log2 6:04 AM 6:19 AM is equal to times in column C
log3 6:07 AM 6:22 AM
log4 6:20 AM 6:35 AM
Many thanks!!
Hardik