I normally start my starter 2 nights before brewing. The night before brewing I chill it in the frig (24 hrs later). The next morning I take it out, decant, and let it warm itself to be pitched later that day.
In all but 1 case it's worked great, tons of yeast activity. The last brew day a few weeks ago, for the first time, I got nothing. I pitched it anyway, figuring it'd eventually go. 24 hours later, still nothing. So I threw some S-05 in instead, and of course it took off as expected. (I highly recommend having some dry yeast on hand at all times as a backup).
And, for the first time, I have sulfur flavored stout. I'm letting it go longer hoping it'll work out, but I think it was the "dead" yeast. I won't do that again. I'd suggest if at all possible hit the LHBS and get more yeast and pop it right away, check if it's working or just pick up some dry yeast. Hope you have that option.