There is a reason leap year is only once every four years 
Looks like there is a bug which does not allow Workspace studio to launch.
Workaround is one of two things
- For today, if there is a corresponding classic tool, use that instead
- Change your system time back to 2/28, launch Workspace Studio and then reset system time back to 2/29
We have since with held food and water from the toolset team for this issue

Sorry about this, we will fix in the code. If this workaround doesn't work for you, PM me via thwack and we will see if there is another workaround.