If the names are in one column and the times in another the sumif() formula works well:
SUMIF(range, criteria, sum_range) Adds the cells specified by a given criteria. Range is the range to which the criteria are to be applied. Criteria is the cell in which the search criterion is shown, or the search criterion itself. In the criteria section, you can use a question mark (?) to match a single character or an asterisk () to match a sequence of characters. If you'd like to find an actual question mark or asterisk, you can type a tilde (~) before the question mark (?) or asterisk (). Sum_range is the range from which values are summed, if it has not been indicated, the values found in the Range are summed.
The other option is a pivot table. Which is more complex.
If the names and data are in the same column, a lot more work will be needed.