Format Cell When time is Past

[rskip]

I have a cell for current time (C4) (Pressing F9 to refresh, and a list of times, 01:00, 02:00, 03:00 etc.(C10, C11, C12) I want to turn the the cells with a static time (01:00, 02:00 etc) red when the time passes, I have conditional formatted the cells C10, C11, C12 with =C10<C4 (RED) etc. However they do not turn Red. In Google sheets this works, however not in excel.
Thoughts on what is wrong?
Thanks

 

[bebo021999]

try VBA to update time in real time
in worksheet module (Right click on sheet name/ view code):

Option Explicit
Private Sub Worksheet_Activate()
getTime
End Sub

and module:
(Alt-F11 then insert module)

Option Explicit
Sub getTime()
Dim t As Double
Application.ScreenUpdating = False
t = TimeValue(Now())
Range("C4").Value = t
Application.OnTime t + TimeValue("00:00:01"), "getTime" ' Change to suitable duration, i.e, 1 minute: Timevalue("00:01:00")
Application.ScreenUpdating = True
End Sub

Code starts to run from sheet activate

 

[rskip]

Thanks, and will add to get auto updating. However my problem is the cells I format, when I manually update the time, will not change to the formatted color.