Hi rstrats,

The 'day' ended/started at sunset. The 'day' of the last supper was a Sabbath, being the first day of the feast of unleavened bread.

The next day was when the Passover lamb was killed. That was the 'day' that Christ died and was buried before sunset. He died AND was buried before sunset.

After sunset was the proper Passover meal (night number one) followed by a 'day' of rest.

There is no reason to assume that another 24 hours did not pass, if that was the usual weekly Sabbath from sunset to sunset. It would explain why the women could not go to the tomb until after the following sunset (ie the normal Sabbath -7th day of the week) had ended.

Therefore, Christ had been in the tomb during the 'day' (light) before Passover then 24 hours over over Passover, then 24 hours over Sabbath, and did not rise until the third period of darkness (night) AFTER He had been buried.

I am unclear which 12 hour period you think is missing?