I do something like: service ntp stop 503 date +%T -s "15:10:00"
But after a while it jums forward to the correct time (If I put it forward in time, it seems to be working).
This is a VMWare Linux Debian VM.
If you have the VMWare Linux Tools installed on the Guest, then it will sync the VM's time to the Host's time by default (I believe it's on by default), regardless of NTP settings.
Edit the .vmx file of your VM and add/change
I believe you can also toggle it via GUI if you have the vmware-toolbox X application installed.