Was the feast of unleavened bread celebrated for 8 days (opposed to 7) as it is outside Israel today in Jesus' time? I am wondering if two Seder meals were eaten during Jesus' time the way it is today outside Israel. If so that might help explain why the gospel of John mentiones eating the passover the night he was crucified and yet other gospels say the last supper was when the evening of the day the lambs were sacrificed. This link answers the question regarding today but how was it during Jesus' time?
TO EDIT:
These are the references to the so-called contradiction.  In the Synoptics, Jesus is eating Passover before He suffers.  John portrays the Passover yet to come after He suffers.

Luke 22:15 And he said unto them, With desire I have desired to eat this passover with you before I suffer:
John 18:28 Then led they Jesus from Caiaphas unto the hall of judgment: and it was early; and they themselves went not into the judgment hall, lest they should be defiled; but that they might eat the passover.

This fairly well-known &quot;contradiction&quot; has been explained in a number of ways ranging from the idea John was written centuries later, for religious purposes, to a different type feast (Passover or other), and to the 7 or 8 day view of which this post is about.
Is Passover 7 or 8 Days?
There is no 'contradiction' between the the evangelists once all factors are properly taken into consideration.

The following synchronisation of all four gospel accounts in relation to the sabbath and the passover (at the time of crucifixion) is given by an extensive document available from Academia, written by James Bejon, who occasionally submits articles to SE-Bible Hermeneutics :

A Chronology of Jesus Ministry


  Matt. 27.62, Mark 15.42, Luke 23.54, John 19.31, 19.42. ‘The day of Preparation’ (paraskeu¯e) is the
  day when people prepare for the Sabbath (Fri.n/Sat.d), as is clear from paraskeu¯e’s employment in extra-
  Biblical sources (Ant. 16.6.2, Did. 8.1, etc.) as well as eqvt. expressions in Aram. (Torrey 1931:234-237).
  
  In fact, the word paraskeu¯e still designates a Friday in modern Greek today. Some scholars (after Zeitlin
  1932:263) take the ‘day of preparation’ to denote ‘the day when people prepared for the Passover meal’,
  i.e., 14th Nis., which allows them to assign the crucifixion to a day other than a Friday. But, while
  such claims are linguistically possible (cf. BDAG paraskeu¯e), they are doubtful given how standardly the
  term ho paraskeu¯e is employed to denote a Thu.n/Fri.d in ancient literature (Bacchiocchi 2001:23-24).
  
  Besides, they do not fit the context of the passion narratives.
  
  Consider, for instance, John’s explanation
  of why Jesus’ legs would have been broken: “because it was the day of Preparation” and “[because] the
  Jewish leaders did not want [Jesus’ body] left on the cross on the Sabbath, since that Sabbath was a high
  day (lit. ‘the day of that Sabbath was great’)” (John 19.31). John’s point is as follows: Jesus’ body was
  taken down because the Sabbath (Fri.n/Sat.d) after Jesus’ death coincided with the start of the feast of
  Unleavened Bread (Lev. 23.6-7), which made that Sabbath a day of rest for two reasons, and hence an
  especially significant one (cf. John 7.37, where the last day of the feast of Tabernacles [Lev. 23.34-36]
  is likewise referred to as a ‘great [day]’). No other interpretation of John 19.31 really adds up.
  
  Some
  commentators think John refers to the day after Jesus’ death as a Sabbath because it was the 1st day
  of Unleavened Bread. But, aside from Yom Kippur, no ‘rest day’ other than a Fri.n/Sat.d is referred to
  as a ‘Sabbath’ (Gr. sabbaton) in Scripture. (In general, the OT refers to a high day as a šabb¯atôn [LXX
  anapausis], while it refers to the 1st day of Unleavened Bread in particular as a miqr¯a c q¯odeš [LXX kl¯etos
  hagios].) And, even if the 1st day of Unleavened Bread could be referred to as a Sabbath, it would still not
  explain John’s statement; indeed, it would reduce it to a mere tautology (‘the feast day happened to be
  a feast day’), akin to a statement like ‘Christmas day happened to coincide with a festive holiday’.
  
  (John
  need merely have said, ‘Since it was the day of Preparation, and since the bodies should not remain on
  the cross on a high day...’.) The order of events set out in the synoptic Gospels underlines the point.
  Jesus dies on the “preparation day”, which is explicitly stated to be “the day before the Sabbath” (Mark
  15.42, etc.), and, once “the Sabbath [is] over” (a reference, one would assume, to the same Sabbath
  mentioned six verses beforehand), the women come to anoint Jesus’ body with spices on “the 1st day of
  the week” (16.1-2 cf. Luke 24.1, etc.). That the Synoptics would refer (without a word of explanation)
  to the 1st day of Unleavened Bread simply as “the Sabbath” is hard (though not impossible) to imagine.
  
  Besides, the Gospels only mention the passage of a single ‘Sabbath day’ between the crucifixion and the
  1st day of the week. The sequence of events is clear: Jesus dies on the preparation day; the next day is
  the Sabbath; and the day after it is the 1st day of the week as well as “the 3rd day” since the crucifixion
  (Matt. 16.21, Luke 9.22, 24.21, 24.46, Acts 10.40, 27.19, 1 Cor. 15.4, Bacchiocchi 2001:22-28).