the datedif formula is having a problem.
=DATEDIF(A1,B1,"y")&" years, "&DATEDIF(A1,B1,"ym")&" months, "&DATEDIF(A1,B1,"md")&" days "&TEXT(MOD(B1-A1,1),"h "" hours "" m"" minutes "" s ""seconds""")
Format: Date/time format (mm/dd/yyyy hh:ss)
Consider
A1= 10/6/2013 18:00
B1= 10/6/2013 18:00...