Related to your question about the timing of when we say Hallel, here is some explanation I received this year about it. (I remember last year Rabbi Bar Hayim discussed it similarly when I attended his minyan in the days leading up to the chag. There is a halachic problem in departing from the practice of the entire nation as Rabbi Goren ZTL pointed out.
"Meshulash" for Yom Tekuma Yisrael (Yom HaAtzmaout)
(To download the Al HaNissim prayer, go to
http://machonshilo.org/en/images/stories/files/Al_HaNissim_YA_YY_Revised.pdf)
As was the case last year, the observance of Yom HaAtzmaout is on the 6th of Iyyar although the State of Israel was actually declared on the 5th of Iyyar.
The holiday was delayed so that the Memorial Day Services of the 4th of Iyyar could begin tonight--Sunday night--rather than Saturday night and preserve the sanctity of the Shabbat avoid the temptation to prepare for the various ceremonies or drive to them on the Shabbat.
If Judaism lends importance to actual date of an event, how can we reconcile the following issues:
* While Rav Goren zt"l ruled that the proper day should be observed, how can we separate ourselves from the public who observes the deferred day?
* When should we recite the Hallel prayer? Isn't the recitation of the Hallel a prayer in vain if we're not saying it on the day of the miracle?
* When do we add the Al-HaNissim prayer to our Birkath HaMazon and Shmona Esray?
Read the rest of the story at
http://kitniyot.blogspot.comI have posted the rest here:
Rav Bar-Hayyim suggests that we look to "Purim Meshulash" for the answer and rules that the festivities and customs of the day should be divided into two:
* On the 5th of Iyyar (tonight and Monday), we should include the Al HaNissim additions to the Shmona Esray and the Birkat HaMazon. The special Torah reading should also be said on this day. These actions commemorate and sanctify the actual day of the event.
* On the 6th of Iyyar (Monday night and Tuesday), we should join the public celebrations of the deferred day and recite Hallel (with a beracha), Shechechiyanu and the "She Assa Nissim" prayers. This enables us to commemorate and sanctify the observed date and join the public celebrations.
The additions to the tefila should occur even when the 5th of Iyyar is observed as the Memorial Day for fallen Israeli soldiers and those who were murdered in terrorist attacks.
This is the case this year. To download the Al HaNissim prayer, go to
http://machonshilo.org/en/images/stories/files/Al_HaNissim_YA_YY_Revised.pdfChag Sameach LeGeulah Shelayma!