Yizkor on Joyous Holidays

Why do you think a Yizkor (memorial) service is traditionally held to remember our deceased loved ones even on some joyous holidays such as Passover and Sukkot?

We mention our deceased on the holy days because remembering them and pledging charity on their behalf, particularly on these holy days, helps elevate their souls.

I would like to suggest that remembering the deceased can actually bring a certain sense of joy. We believe that there will be a resurrection of the dead, and we anticipate a time when we will all be celebrating together once again.