Converting date and time into datetime variable

[Dorothea Ekoka Mbassi]

Dear community,

I have a dataset with one variable entrydate (dd.mm.yyyy; format str10; all in 2019 or 2020) and one variable entrytime (hh:mm; format str5; 24h format). I also have exitdate and exittime variables of the same type. I'd now like to generate entrydatetime and exitdatetime variables to be used in survival analysis.
After having tried several solutions from this forum, I got as far as this:

generate double dentrydate = date(entrydate,"DMY")
generate double dentrytime = clock(entrytime,"hms")
format dentrydate %tdDD/NN/CCYY
format dentrytime %tcHH:MM
generate double entrydatetime=dentrydate*24*60*60*1000+dentrytime
format entrydatetime %tcDD/NN/CCYY_HH:MM

I don't get any error code. However, dentrydate is displayed correctly (same way as entrydate to the human eye), but dentrytime and entrydatetime are only displayed as "."
What do I need to change in order to correctly display entrydatetime as DMY HH:MM? I'd like to be able to calculate differences of exitdatetime-entrydatetime for my survival analysis.

Many thanks in advance for Your advice.

[Andrew Musau]

* Example generated by -dataex-. For more info, type help dataex
clear
input str10 entrydate str5 entrytime
"10.11.2019" "22:30"
"25.02.2020" "00:15"
end

g double wanted= Clock(entrydate+" "+entrytime, "DMYhm")
format wanted %tcDD/NN/CCYY_HH:MM

Res.:

. l

     +------------------------------------------+
     |  entrydate   entryt~e             wanted |
     |------------------------------------------|
  1. | 10.11.2019      22:30   10/11/2019 22:30 |
  2. | 25.02.2020      00:15   25/02/2020 00:15 |
     +------------------------------------------+

[Dorothea Ekoka Mbassi]

Much more efficient, thank You so much once again, Andrew!