datenum problem with conversion

I have a question. I am trying to use datenum function as below. Question: why ans1=ans2? Am I using format wrongly? Thank you!

ans1 = datenum('4:30:00 PM','HH:MM:SS PM')
ans1 =

     7.3670e+05
  ans2 = datenum('2:30:00 PM','HH:MM:SS PM')

ans2 =

     7.3670e+05

[Stephen23]

Are they the same?

>> format longg
>> datenum('4:30:00 PM','HH:MM:SS PM')
ans =
               736696.6875
>> datenum('2:30:00 PM','HH:MM:SS PM')
ans =
          736696.604166667

[Star Strider]

Déjà vu

Answer 1

[Star Strider]

They’r not the same. Use the format function to display the entire number in full precision:

format long g
ans1 = datenum('4:30:00 PM','HH:MM:SS PM')
ans2 = datenum('2:30:00 PM','HH:MM:SS PM')

ans1 =
               736696.6875

ans2 =
          736696.604166667

[Jan]

Alternatively:

ans1 = datenum('4:30:00 PM','HH:MM:SS PM')
ans2 = datenum('2:30:00 PM','HH:MM:SS PM')
ans1 - ans2
% And:
(ans1 - ans2) * 86400