I tried to convert Excel date character to date-time class using POSIXlt. This is an example of my data: "01:56:00 06-Apr-2017".
For the format, I used the character string giving a date-time format as used by strptime.
I tried as.POSIXlt(new_dtime, format = "%H:%M:%S %d-%b-%Y"), but it resulted in a bunch of NA. I am sure that the problem is related to the month abbreviation, despite I used  %b as strptime suggests. Any help?