Scott's episodes of NCIS will air on March 25 and the following week. It's a Tuesday, it's CBS and it's 8pm. If it's easier to remember - it's opposite SHIELD.
If the eps are "positively received" CBS will spin them off to a series. I don't know what could be more positive than being the number 1 show on TV, but... I'd be happy to tweet at sponsors during breaks if someone could find the correct twitter accounts for said sponsors.
RT @HaleyMcLintock: "@SFXmagazine: Just watched Scott Bakula autograph John Barrowman's butt cheek." http://bit.ly/RaOQTi #LondonTrek