First of all, I think the 90 days thing is great.

I remember that the idea was mentioned that it takes 90 days neurologically to break an addiction and form a new habit; additionally, the idea in Halacha that after 30 days one is officially accustomed to the new Shemoneh Esrei was also mentioned.

The reasoning was as follows: 30 days x 3 Shemoneh Esreis a day = 90 Shemoneh Esreis, the magic number for addictions as well.

Not so fast, though. #1, the opinions that allow you to say the proper Shemoneh Esrei many times on the 2nd day of Pesach (or on Shemini Atzeret) require you to say the phrase 100 times, and not 90 times.

Second, the 30 x 3 calculation completely forgets about Mussaf (at least for Mashiv Haruach uMorid Hageshem; I'm not sure about v'tein beracha or v'tein tal umattar livracha) that is said on Shabbos and Yom Tov.

Assuming that in 30 days, you have 3 or 4 Shabbosses, and several Yamim Tovim, the number is closer to 100. (There would be a difference on Sukkos and Shavuos, though).

By no means am I at all knowledgeable in Halacha; all I am trying to say is that the analogy is strained, and you can't compare the neuroscientific findings to Halacha.

Of course, the program is still praiseworthy; I wish I could make it to 90 days.

Welcome, Chachaman.

I recently worked on the sugya, therefore I can talk as if I know what I'm saying.
You said it's 100 not 90, see שולחן ערוך סוף סי' קיד where it says 90. True, the Chasam Sofer (brought in Mishna Berura there) based on your'e next question from Mussaf says you may need 101, but he himself says the main halachah is 90 as mentioned in Tur and Shulchan Aruch. As for the Musaf issue, and a opposite problem with ותן טל ומטר which not said on Shabbos, see M"B that disscusses at lengh those questions.

BTW, I have different technical problem with 90 days. The original source for the whole idea is a Yerushalmi which says after 90 days one musn't repeat Shemona Esrai, based on that the Maharam Mirutenburg made the cheshbon of 90 times. So the amount of days to break a habit is 30 not 90!?!

But most importantly, I wish you much hatzlochoh in in staying squeaky clean forever, from 30 to 90 and then to 100 and on.

And let's not forget - it's really only one day at a time - yesterday does not exist anymore - tomorrow does not exist yet - so you're left with one single day - make the most of it!

MT

You are correct. I remember reading in the laws in the back of the Artscroll siddur that you could say it 100 times and be good, but I went back and checked. I found:

75. "On Shemini Atzeres he may repeat the passage mechayeh meisim...one hundred and one times [if he said this only ninety times it is sufficient post facto.]"

And indeed, looking in the Mishnah Berurah 114:37, I found:

"And even though in the next seif the mechaber wrote that 90 times is enough, and in 30 days there are more than 90 [Shemoneh Esreis] because of the Mussaf prayers, many Acharonim have already answered that "30 days" means "like the amount of regular prayers in 30 days", that is 3 times a day. If so, according to their words, we don't need a complete 30 days, but rather once one has completed 90 Shemoneh Esreis one's tongue is immediately accustomed to saying the Shemoneh Esrei as according to Halacha.

And for the matter of "v'tein tal umattar livracha", for in 30 days there are less than 90 Shemoneh esreis (because on Shabbos and Yom Tov [included in the 30 day count] the Shemoneh Esreis only have 7 blessings), a stringency would sprout from this ruling: that one would need to repeat the Shemoneh Esrei [if one isn't sure whether one said "v'tein tal umattar livracha" or not] out of doubt even after 30 days.

And from the words of the Gra and other Acharonim, it is implied that the main principle is dependent only on the passage of 30 days, whether for stringency or for leniency. And as for the practical halacha, we should be lenient on both sides [i.e. either 90 shemoneh esreis or 30 days, whichever comes first], because of the principle that we are lenient with regard to doubts about Berachot.

The Taz writes that if by accident or intent one didn't daven for one or two days from within the 30 days, nevertheless the chazakah isn't damaged and you wouldn't need to wait extra days to make up for the days that you didn't daven."

114:41--"And in the responsa of the Chasam Sopher...he rules that initially, one should say it 101 times; however, bedieved, we can't rule with regard to someone who only said it 90 times that they should go back and pray again, opposite to the Shulchan Aruch's ruling [that you only need to say it 90 times]."

Sorry I quoted the whole thing; I just thought that it was so interesting.

We can learn out a mussar ruling from the Taz: even if you didn't pray for one day--that is, you fell--you haven't lost all your progress, and the chazakah hasn't been destroyed.

Thank you for pointing me to the source in Shulchan Aruch!