Interpolating Data At 5-minute Resolution Down To 1-minute Resolution

Entering a formula which will allow me to expand my data set by interpolating between sets of x,y values. My data set is in 5-minute resolution and I would like to interpolate so that I can output a new set of x,y values in 1-minute resolution. Here is my example of what I have and what I would like my end result to be, and also I have attached a sample of my data set in the below excel file:

Original data set
Date TimeTemperature oC
6/12/13 13:30 18.28
6/12/13 13:35 17.9
6/12/13 13:40 17.9

Desired data set
Date TimeTemperature oC
6/12/13 13:30 y
6/12/13 13:31 y
6/12/13 13:32 y
6/12/13 13:33 y
6/12/13 13:34 y
6/12/13 13:35 y
6/12/13 13:36 y
6/12/13 13:37 y
6/12/13 13:38 y
6/12/13 13:39 y
6/12/13 13:40y

datetime_temp.xlsx