Why do Jehovah's Witnesses hold a "commemoration of the death of Jesus Christ"? For the last several years, I have received mailings from Jehovah's Witnesses that say the following:

Lo invitamos a acompañarnos a la Conmemoración anual de la muerete de Jesuscristo. Este es el día, la hora y el lugar donde se celebrará:
(My translation) We invite you to join us in the annual commemoration of the death of Jesus Christ. This is the day, the time and the place where it will be held:

It then gives the address of a local Jehovah's Witnesses church and the time of a service, which is on the Saturday between Good Friday and Easter Sunday. But nowhere in the pamphlet does it mention those two days, the resurrection of Jesus, or anything else that's related to it.
Why would Jehovah's Witnesses hold a &quot;commemoration of the death of Jesus Christ&quot; on the Saturday between Good Friday and Easter when other Christian denominations do not? And is it noteworthy that this pamphlet doesn't mention the resurrection of Jesus on the following day?
Jehovah's Witnesses observe the Memorial of Jesus' Death (also called the Lord's Evening Meal) after sundown on the day that coincides with Nisan 14th according to the ancient Jewish calendar. Nisan 14th may be on any day of the week from year to year, so the fact that it's on a Saturday this year has no relevance. In 2017 it was on a Tuesday, and in 2016 it was on a Wednesday.

Jehovah's Witnesses commemorate the death of Jesus Christ because Jesus commanded that we do so at Luke 22:19 saying, "Keep doing this in remembrance of me." This command is reemphasized by Paul at 1 Corinthians 11:23-25.

Jesus' resurrection is also core to the Christian faith, but we are not commanded to commemorate it, nor is there evidence that early Christians celebrated it until the 2nd century. Jehovah's Witnesses don't celebrate Easter because of its association with pagan customs. God does not permit his servants to mix false religion with true religion. (1 Corinthians 10:21)