Zend certified PHP/Magento developer

To find out the latest time in excel

All I just want to find the maximum/latest time in a time range, I use max function to find out always, but if the time surpasses midnight(00:00)then it gives result only the maximum time upto 23:59. I need latest time even if surpasses midnight say example 00:50, 01:30 etc Eg I get late output timings like 23:00, 23:30, 23:45, 00:15, 01:30 like this.

kindly help me to get the latest timings