'Today' in the Bible

Also a bullock and a ram for peace offerings, to sacrifice before the LORD; and a meat offering mingled with oil: for to day the LORD will appear unto you.

And Aaron said unto Moses, Behold, this day have they offered their sin offering and their burnt offering before the LORD; and such things have befallen me: and if I had eaten the sin offering to day, should it have been accepted in the sight of the LORD?