Yes, Sabbath is the same, friday sunset to saturday sunset. But less strict, don't have all the extra jewish laws iykwim. The bible just says rest and do no work so I guess its up to the individual to decide what that means for them whereas you have it all written down I think????
With the passover, christians have the passover as feast day, and last day of unleavened bread as feast day (instead of first 2 and last 2 days).
Also, christianity sees the 'old' meaning of the feasts (e.g. for passover exodus from egypt) and also the 'new' meaning (e.g. jesus was the passover lamb). So, all of the 'old' (sorry, don't know the right word) events that are celebrated by the festivals are symbols for what happened in jesus day and what is to happen in the future. Does that make sense??

Found these references on a the internet, haven't actually looked them up yet:

Feast of Trumpets: Leviticus 23: 23-25, Matthew 24: 30-31, 1 Thessalonians 4: 16-17, Revelation 11:15

Last Great day (or eigth day): Leviticus 23: 36, John 7: 37-38.