According to Project Spark's developer, Team Dakota, the title is set for a tentative February beta window. That's not set in stone though.
The info came during a Twitch live stream with Team Dakota, in which they issued the Xbox One beta window of 'February'. They did however warn that it could slip to March, based on potential development challenges between now and then.
Anyway, if you're interested, you can check out the full Twitch steam here
Are you looking forward to Project Spark? Did you sign up for the beta? Let us know in the comments section or over on Facebook