Davening on Yom Tov
This is the approved revision of this page, as well as being the most recent.
Taking out the Torah
- Some have the minhag to say the 13 midot when taking out the Torah on Yom Tov. Others don't do so, and each side has what to rely on. 
- If one began with the weekday Shmoneh Esrei, the laws are the same for if one began the weekday Shmoneh Esrei on Shabbat. For the relevant laws, see the Shabbat_Davenings#Saying_the_weekday_Shemoneh_Esrei_by_mistake page. 
- With regards to the laws of Mussaf, see the Mussaf page.
- Some say that if davening extended until chatzot one should say mincha before eating one's yom tov meal.
Mistakes in Yom Tov Tefillah
- If on Yom Tov you davened the Shabbat Shemona Esrei and thought it was Shabbat you don’t fulfill your obligation. If you fixed the conclusion of the Shabbat bracha within a toch kdei dibbur according to many poskim you fulfill your obligation.
- If on Yom Tov you davened the Shabbat Shemona Esrei and knew it was Yom Tov according to some poskim you fulfill your obligation.
- If on Yom Tov you mentioned Yom Tov in the middle of bracha and concluded with Shabbat according to a minority of poskim you fulfill your obligation. Many others argue one doesn’t fulfill his obligation. If it is within Toch Kdei Dibbur one should fix it and say Mikadesh Yisrael Vehazmanim. If one remembers after Kedi Dibbur one should return to the bracha of Atta Bechartanu.
- If on Yom Tov you mentioned Shabbat in the middle of the bracha and not Yom Tov and then you conclusion with Yom Tov according to some you fulfill your obligation but some disagree.
- In Tefillah of Yom Tov if someone said Mikadesh Yisrael and didn’t add Ve’hazmanim some say that he did fulfill his obligation, while others say he didn’t fulfill his obligation.
- If it is Shabbat Yom Tov the conclusion of the bracha is Mekadesh Hashabbat V’Yisrael V’hazmanim. If someone made a mistake and said Mekadesh Hashabbat only he fulfilled his obligation. If someone made a mistake and said Mekadesh Yisrael V’hazmanim only according to many Ashkenazic poskim he didn’t fulfill his obligation but according to Sepharim he did fulfill his obligation and shouldn’t go back.
- Outside Israel, one should say complete Hallel on all 9 days of Sukkot and Shemini Aseret, the first 2 days of Pesach, and the 2 days of Shavuot. 
- In Israel, one should say complete Hallel on all 8 days of Sukkot and Shemini Aseret, the first day of Pesach, and on Shavuot. 
- See Kitzur Shulchan Aruch 76:16-19 who puts the halacha for Shabbat and Yom Tov together.
- Maaseh Rav (n. 171) of Gra states that if davening on Yom Tov went past chatzot they should say mincha before the meal.
- The Shulchan Aruch 487:1 implies that if you fixed your Shabbat bracha within toch kdei dibbur and all along knew it was Yom Tov then it is fixed. However, he implies that if you didn’t realize it was Yom Tov then it can’t be fixed even within toch kdei dibbur. The Magen Avraham 487:2 points out that many disagree and hold that it can be fixed within toch kdei dibbur even if you didn’t realize it was Yom Tov in the beginning of the bracha. Mishna Brurah 487:5 holds like that opinion that within toch kdei dibbur it can be fixed.
- Shulchan Aruch 487:1 writes that if you knew it was Yom Tov and said the Shabbat Shemona Esrei you can fix the middle bracha within toch kdei dibbur. He implies that if you didn’t fix it even though you knew it was Yom Tov you don’t fulfill your obligation. That is how Magen Avraham 487:2’s explains Shulchan Aruch.
- Magen Avraham 487:2 writes that automatically if you mentioned Yom Tov in the middle of the bracha then you fulfill your obligation even if the conclusion is incorrect. However, the Magen Avraham himself questions this explanation. Machasit Hashekel explains that the Magen Avraham retracted from his original idea. Bear Heitiv quotes the original idea of the Magen Avraham.
- Pri Chadash 487:1, Mamaar Mordechai 487:1, Mishna Brurah 487:4 and 487:11, Aruch Hashulchan 487:4, Kaf Hachaim 487:15, Kitzur Shulchan Aruch 76:23
- Magen Avraham 487:2
- Mamaar Mordechai 487:1 disagrees with the Magen Arvaham. Aruch Hashulchan 487:4 agrees. However, Pri Megadim E”A 487:2 writes that we wouldn’t remake the bracha out of doubt. Kaf Hachaim 487:16 agrees.
- The Gemara Pesachim 117b has a dispute between the elders of Pumpedita and Rava in tefillah whether you should say Mikadesh Yisrael or Mikadesh Yisrael Vehazmanim on Yom Tov. Magen Avraham 487:1 writes that although we initially rule that you should say Mikadesh Yisrael Vehazmanim after the fact if you followed the other opinion you fulfill your obligation. Chok Yakov 487:4 argues that you don’t fulfill your obligation since according to the halacha you changed the bracha of chazal. Pri Megadim E”A writes that if you mentioned Yom Tov in the middle and just concluded with Mikadesh Yisrael certainly you fulfilled your obligation. Kaf Hachaim 487:17 agrees.
- Shulchan Aruch 487:1
- The Knesset Hagedola writes that if you only concluded with one of the two conclusions you fulfilled your obligation. The Pri Chadash 487:1 that you don’t fulfill your obligation since you changed the institution of chazal. The Biur Halacha 487:1 writes that even though it is a major dispute in his understanding of the Gemara Bavli and Yerushalmi one does fulfill one’s obligation since he mentioned Shabbat which is the primary obligation to be mentioned. Kaf Hachaim 487:20 agrees.
- Knesset Hagedola holds that mentioning one of the two conclusions is sufficient after the fact. Pri Chadash argues since you changed from the establishment of chazal. Biur Halacha concludes that with respect with forgetting Shabbat which is the primary obligation of the day one doesn’t fulfill his obligation. Chok Yakov 487:4 agreed with the Knesset Hagedola. Kaf Hachaim 487:20 writes that out of doubt for the Knesset Hagedola one shouldn’t repeat the bracha.
- Gemara Erchin 10a, Rambam (Megillah VeChanukah 3:6-7)
- Gemara Erchin 10a, Rambam (Megillah VeChanukah 3:6-7)