The Hagaddah Reads:
It could be from Rosh Chodesh, but the verse says, "On that day." If on that day then it may be during the day, the verse says, "Because of this." Because of this I only said at the hour when matzah and maror are before you.Light of Redemption: A Passover Haggadah Based on the Writings of Rav Kook:
The Midrash Mechilta (Bo 17) from which this passage is taken suggests that we should be able to fulfill the mitzvah of relating the story of coming out of Egypt from the beginning of the month of Nisan. This is due to an interpretation of the verse in the Torah that commands us to relate the story of the exodus from Egypt to our children. This verse is a crucial source for the entire mitzvah of the Seder night.Rav Kook continues to go on and explain why Rosh Chodesh could not be the time, but the point here is beautiful. We became free when we were given the mitzvah of Rosh Chodesh, we were no longer slaves. We looked like slaves, we acted like slaves, but in our minds we were not. We made our own time.
"You shall tell your son on that day, 'Because of this God did this to me when I left Egypt' " (Shemot 13:8). The midrash suggests that theoretically we could perform this mitzvah starting from Rosh Chodesh Nisan.
This is because the redemption from Egypt actually started on the 1st of Nisan. On this day the Jewish people recieved the first mitzvah, that of establishing a lunar calendar (see Shemot 12:2 adn Rashi on the Torah, BeReishit 1:1). At this point the Jewish people introduced their own way of counting time and had control of their time; they started to be free from the slavery of Egyptians.
This reminds me very clearly of a scene in The Hurricane where Denzel Washington's character Hurrican Carter refuses to act like an inmate.
I will bend time to my own clock.It works, when we control our own time we are no longer their slaves.
When the prison is awake, I will sleep.
When they sleep, I will wake.
I will live neither in their cell...
nor in my own heart,
only in my mind...
and my spirit.