Three days and three nights

Isn't Jesus a false prophet since he wrongly predicted in Matt. 12:40
that he would be buried three days and three nights as Jonah was in the
whale three days and three nights? Friday afternoon to early Sunday
morning is only one and a half days.

Biblical Errancy Pamphlets by Dennis McKinsey Pamphlet 2 Q4.

Answer:

The problem: According to Mat 12:40 Jesus will be three days and three nights in the heart of the earth. But if he was crucified on Friday and rose on Sunday morning he was actually dead for less than two days.

(Mat 12:40 NIV) For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth.

Jesus also taught on numerous occassions that he would be raised on the third day, see Mat 16:21 as just one example

(Mat 16:21 NIV) From that time on Jesus began to explain to his disciples that he must go to Jerusalem and suffer many things at the hands of the elders, chief priests and teachers of the law, and that he must be killed and on the third day be raised to life.

Because of the reference to "the third day," and because in Matthew 12:40 Jesus refers to "three days and three nights," some have thought that Jesus had to spend at least 72 hours in the grave. This upsets most chronologies of the death and resurrection of Jesus, and is unnecessary - because it doesn't take into account the use of ancient figures of speech. Rabbi Eleazar ben Azariah (around the year 100 AD) explained this way of speaking when he said: "A day and a night make a whole day, and a portion of a whole day is reckoned as a whole day." This demonstrates how in Jesus' day, the phrase "three days and three nights" did not necessarily mean a 72-hour period, but a period including at least the portions of three days and three nights. See also its use in Est 4:16 - 5:1

(Est 4:16-17 NIV) "Go, gather together all the Jews who are in Susa, and fast for me. Do not eat or drink for three days, night or day. I and my maids will fast as you do. When this is done, I will go to the king, even though it is against the law. And if I perish, I perish." {17} So Mordecai went away and carried out all of Esther's instructions. (Est 5:1 NIV) On the third day Esther put on her royal robes and stood in the inner court of the palace, in front of the king's hall. The king was sitting on his royal throne in the hall, facing the entrance.

We see in the above passage that she broke her fast on the third day.

see also Glenn Miller's reply ...well, is it 'after' 3 days or 'on' the 3rd day?!

for a more interesting answer see Jesus Christ's Death, Burial, and Resurrection as a Fulfillment of the Sign of the Prophet Jonas Matthew 12:40 by Danny R. Bowen