How often may Birchas Hareiyah be recited?
All the blessings that are said over the sight of an item [i.e. Birchas Hareiyah] are not to be repeated if one re-saw the same item within thirty days of the previous sighting and subsequent blessing. [Thus, if one saw the Great-Sea on the 1st of Marcheshvan and said the blessing, and then re-saw it again on the 30th of MarCheshvan, a blessing is not repeated. If however he saw it on the 2nd of Kisleiv, the blessing must be repeated. ]
How to count the thirty days: The thirty days are counted starting from the day of sight [and blessing]. (For example, if he saw [the item and said a blessing] on Sunday, then if he sees the item again on Tuesday four weeks later, he may say the blessing again.) [Thus, the blessing is to be repeated beginning from the 31st day from the original sighting.]
If one saw another item of the same kind: If one saw a different item of the same kind [within thirty days], such as he saw a different king or a different sage, then a blessing is to be repeated. This applies even if he saw the two kings/Sages immediately one after the other, nevertheless the blessing is repeated. This however is with exception to a Jewish cemetery, and the blessing of Mishanhe Habriyos and Shecacha Lo Beolamo. This means as follows: If one saw another grave/cemetery within thirty days of another sighting [and blessing], the blessing is not repeated. [This applies even if the second cemetery is in a different city.] Likewise, if one saw another of the same type of extraordinary creation after having originally seen one and having said the blessing, the blessing is not to be repeated at all even after thirty days. [Thus, if one saw a strange creature and said the blessing and then saw another one of those same strange creatures, he does not repeat the blessing even after thirty days. If, however, he saw a strange creature of a different species, the blessing is to be repeated.]
· How often: The blessing may be said every thirty days.
· How to calculate the thirty days: The thirty days are counted starting from the day of sight and hence if he saw it on Sunday he may repeat the blessing again on Tuesday four weeks later, which is the 31st day.
· Saw different item within thirty days: If one saw a different king or different sage, even immediately after the 1st king/Sage the blessing is repeated.
· One does not recite blessing on any cemetery, even if it is a different cemetery, unless 30 days have passed since he last saw a cemetery and blessed on it.
· Mishaneh Habriyos and Shekacha Lo are only said the first time one sees the beauty.
If one saw the item and did not say the blessing and then re-saw it within thirty days, may the blessings be recited?
By those matters that receive a blessing every thirty days, seemingly the blessing may be recited.
 Seder 13/13; Luach 12/19; Michaber 224/13 and 218/3; Tur and Rosh; Tosafus Brachos 54a
 Luach ibid
 Admur Seder and Luach ibid in parentheses; Abudarham, brought in M”A 218/4; Elya Raba 218/2; Mateh Yehuda 224/2; Nimueki Orach Chaim 224
Other opinions: Some Poskim rule that we do not include into the thirty days the day in which the original sighting and blessing took place. Accordingly, if the blessing was recited on Sunday, it may only be repeated on Wednesday, four weeks later. [M”A 218/4; Implication of Levush 218; Chayeh Adam 68/4; Aruch Hashulchan 218/5; Kaf Hachaim 218/12 that so rule Achronim; See Piskeiy Teshuvos 218/4]
 Admur Seder and Luach ibid; M”A 224/10; Raavad, brought in Radbaz 1/296
 Admur Seder and Luach ibid; Mateh Yehuda ibid; Yad Eliyahu 30 based on M”A ibid, brought in Shaareiy Teshuvah 224/9; Pischeiy Teshuvah 224 in name of Amudei Or; Poskim in Kaf Hachaim 224/38; Implication of M”B 224/17; Nimueki Orach Chaim 224/4 “Safek Brachos Lihakel”
The reason: As all the corpses have the same status and all receive the same judgment. It is not similar to the honor of a king and wisdom of a Sage which differentiates between kings and Sages, and hence it suffices to recite one blessing each day. [Luach ibid; Yad Eliyahu ibid]
Other opinions: Some Poskim rule a blessing is recited upon seeing another grave. [Halachos Ketanos 1/112; Birkeiy Yosef 224/6 in name of Radaz 2/296 and Rav Avaraham Azulai; Beir Heiytiv 224/9; Shaareiy Teshuvah 224/9; Leket Yosher Y.D. p. 99; Orchos Chaim of Rav Avraham Halevi; Shulchan Hatahor 224/5; Kitzur SHU”A 60/12; Birchas Habayis 29/8; Aruch Hashulchan 224/8; Keren Ledavid 58; Yabia Omer 5/7; Beir Moshe 2/17; See Piskeiy Teshuvos 224/11 footnote 58]
 Luach ibid
 Admur Seder ibid; 1st opinion in Luach 13/21 and 22; Michaber 225/9; Tur 225 in name of Raavad Teshuvos 202; See Piskeiy Teshuvos 225/23
The reason: As the blessing is only said by the first time that the great novelty and wonder is seen. [Admur ibid]
If one saw a nicer creation of the same species: In the Luach 13/22 Admur concludes that even according to the first opinion “Unless he saw a nicer creation, in which case a blessing may be repeated even within thirty days.” This is omitted in the Seder ibid. The above ruling in Luach is based on Michaber 225/10, although some Poskim rule it may only be repated after thirty days and not within thirty days. See Piskeiy Teshuvos 225/23
Other opinions: Some Poskim rule that one may repeat the blessing of Mishaneh Habriyos and Shekacha Lo Beolamo every thirty days, upon seeing [another creation of- Shaar Hatziyon 225/32] the same species. [2nd opinion in Luach 13/21 and 22; Rama 225/9; Olas Tamid 225/6; Nehar Shalom 225; Shulchan Shlomo 225/7; Aruch Hashulchan 225/13; Ashel Avraham Butchach 225; Shulchan Hatahor 225/14; Keren Ledavid 58; Tzitz Eliezer 12/22; See Shaar Hatziyon 225/32 that even Rama agrees that by same exact creature blessing is never repeated; See Piskeiy Teshuvos ibid footnote 149] Accordingly, some Poskim conclude it is proper to recite the blessing without Hashem’s name. [Admur in Luach ibid; M”B 225/30] Practically, Admur in the Seder omitted this opinion.
 Pashut, as Admur writes “of its like”; Seder of Rav Elyashvili footnote 106; Piskeiy Teshuvos 225/23 footnote 150
 So is implied from the wording of Admur ibid “All the blessings that are said over the sight of an item [i.e. Birchas Hareiyah] if one repeated and saw the same item that he blessed on within thirty days the blessings is not to be repeated.”; See Michaber 218/3