I want to draw a graph on something that happened over 24 hours

e.g.


0700 2 (i.e. 7am, value - 2)
0713 3
0905 12
1307 2
1906 6
2305 9 (i.e. 11.05pm, value 9)


Can I get Excel to put time on the X axis?

Can I get Exel to calculate time difference from 7.13am to 9.05am -
i.e. it's not 0905 - 0713 = 0202; it should be 1hour 52minutes