Timing for the three meals of Shabbat

Hi,

We are taught to eat three meals on Shabbat.

One who is not able to eat a meal Friday night should make it up by eating three meals during the day of Shabbat; this is an acceptable way to catch up. However, the reverse does not work; one who knows that he will not be able to eat two meals during the day of Shabbat may not make it up by eating two meals on Friday night.

The logic may be that the meals of Shabbat are associated with particular times - Friday night, Shabbat morning and Shabbat afternoon. One who has already missed Friday night may make it up by eating an additional meal on Shabbat day, but one may not move the second meal to Friday night when he could do it on Shabbat day.

Alternatively, the reason may lie in our general rule that the honour of the day of Shabbat is greater than the night. [For this reason, one who has the option of making the nighttime meal or the daytime meal greater is supposed to make the daytime meal greater.] Therefore, one should not switch so that he has two meals at night.

Despite the above, one whose only option for three meals is to eat two meals at night should do so.

(Rivivot Ephraim 1:207)

Have a great day,
Mordechai