VIX futures were listed in 2006. They confound and confuse investors in that they often do not move with the VIX itself. Again, it’s that pesky mean reversion. A VIX future is an over/under bet on where the VIX will “settle” on the opening of the day the future expires. They settle based on the opening quote in each applicable SPX option series, so the settlement price can deviate from the range of the actual VIX that day.
VIX futures expire 30 days prior to the next month SPX “regular” expiration, so VIX-piration is always a Wednesday, either two days before or three trading days after a regular SPX expiration.