Use of 想定 in nuance hint

[simias]

I’m confused by this use of 想定 in this hint for the 弁当 vocab:

Shouldn’t it be 予定 or am I misunderstanding the sentence?

[nekoyama]

With 予定 it kind of sounds like they schedule an appointment for the food to be eaten before packing it…

想定 is an assumption, what you imagine will happen. The food is packed under the assumption that it’ll be eaten on the same day.

[simias]

Thank you!