Note: The Jewish calendar date begins at sundown of the night beforehand. Thus all holiday observances begin at sundown on the secular dates listed, with the following day being the first full day of the holiday. (Thus, the first Passoverseder is held on the evening of the first date listed.) Jewish calendar dates conclude at nightfall.
The first two days of Passover (from sundown of the first date listed, until nightfall two days later) are full-fledged, NO WORK allowed holiday days. The subsequent four days are Chol Hamoed, when work is allowed, albeit with restrictions. Chol Hamoed is followed by another two full NO WORK holiday days.