AS A WORKAROUND
When in Excel, you could create a column and insert the following =(LEFT(RIGHT(A2,18),5))
Remember to change A2 to correspond to the first cell with the time information you need to convert. You can then drag this down to populate the rest of the form.
HintWhen you subtract two-time points from this conversion, multiply what you get by 1440 to get the difference in minutes. This is because the difference is always provided in days and you thus need to multiply it by (24*60) to get minutes.