A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
By knowing the numerical value for those times, you can write a lookup table like this:
=LOOKUP(MOD(A2,1),{0,0.25,0.604861111,0.959027777},{"3rd","1st","2nd","3rd"})
Note that for ease of use, it might be better to simply construct a table somewhere with the start times for each shift (don't forget to have 2 entries for 3rd shift) so that you can modify it if need be.