Veset Kavua (Established Veset)


Veset Kavua (Established Veset)

Most women with a regular period expect their menses within a given time range but not on a specific day. A few women are able to predict the time of their menstruation exactly. Halachically, a woman has a veset kavua, an "established period," if her menses follow a consistent and predictable pattern.

The most common forms of the veset kavua are the veset hachodesh, established when three consecutive periods begin on the same date of the Hebrew month, and the veset haflagah, established when four consecutive periods are separated by three equal intervals. The consecutive periods in question must all begin during the same onah (daytime or night-time).

There are other ways of establishing a veset kavua, but they are rare and rather complicated. If a woman notices any consistent pattern (e.g., menstruating on the same date every other month, or at gradually increasing or decreasing intervals), she should consult a rabbi or a yoetzet halacha.

A woman with a veset kavua observes only that veset. She abstains from relations and must perform an internal examination during the onah of the veset. If she forgot, she must do the examination as soon as possible afterwards, and may not engage in relations until she does so.

In contrast, a woman who does not have a veset kavua observes several onot perishah (times of separation): yom hachodesh, the haflagah, and onah beinonit. She abstains from relations and performs an internal examination during each of these onot. If she forgot to perform the examination on the onah beinonit, she must do so afterwards before she may resume relations; however, this is not required for the other onot perishah.

A woman with a veset kavua anticipates bleeding only on the day of the month or after the intervals she has established. If, however, she has a menstrual flow on an unanticipated day, then the following month she observes yom hachodesh and the haflagah from the deviant sighting, as well as her veset kavua. She does not observe onah beinonit.

If on three consecutive occasions the date of the veset kavua passes with no bleeding, then the veset kavua is "uprooted" and she no longer anticipates it. If, however, she subsequently has a menstrual flow in accordance with her former pattern, the veset kavua is immediately reestablished - even if this happens only once, and even if years have passed since the veset kavua was uprooted. A veset kavua can only be permanently uprooted if a new veset kavua is established.

veset kavua may be based on physical symptoms which accompany menstruation, e.g. noticeable cramps that occur at a consistent time before menses (see veset haguf). A veset kavua is most commonly found in association with hormonal treatments (e.g., contraceptive pills - see Vesatot and Hormonal Treatments).

Establishing a Veset Kavua: Graphic Calendars

A woman establishes a veset kavua if her cycle follows a consistent and predictable pattern for three consecutive periods. The most common forms of the veset kavua are the veset hachodesh (date of the Hebrew month) and the veset haflagah (interval):

Veset Hachodesh

A woman establishes a veset hachodesh kavua when three consecutive menstrual periods begin on the same date of the Hebrew month during the same onah (daytime or night-time), as in the following example.

Nissan

A woman begins to menstruate on 15 Nissan during the day.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15   16 17 18 19 20 21
22 23 24 25 26 27 28
29 30          

 

Iyar

Her next menses begin on 15 Iyar during the day.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
    1 2 3 4 5
6 7 8 9 10 11 12
13 14 15   16 17 18 19
20 21 22 23 24 25 26
27 28 29        

 

Sivan

Her next menses begin on 15 Sivan during the day. She has now begun to menstruate on the 15th of the month during the day for three consecutive months. She has established a veset kavua for yom hachodesh.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
      1 2 3 4
5 6 7 8 9 10 11
12 13 14 15   16 17 18
19 20 21 22 23 24 25
26 27 28 29 30    

 

Tammuz

She observes her veset kavua on 15 Tammuz during the day .

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15   16
17 18 18 20 21 22 23
24 25 26 27 28 29  

 

Veset Haflagah

veset haflagah is established when four consecutive menstrual periods are separated by three equal intervals. The last three menstrual periods must all begin during the same onah, as in the following example.

Nissan

A woman begins to menstruate on 15 Nissan during the day.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 (1) 16 (2) 17 (3) 18 (4) 19 (5) 20 (6) 21 (7)
22 (8) 23 (9) 24 (10) 25 (11) 26 (12) 27 (13) 28 (14)
29 (15) 30 (16)          

 

Iyar

Her next menses begin 28 days later, on 12 Iyar during the day.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
    1 (17) 2 (18) 3 (19) 4 (20) 5 (21)
6 (22) 7 (23 8 (24) 9 (25) 10 (26) 11 (27) 12 (28=1)
  
13 (2) 14 (3) 15 (4) 16 (5) 17 (6) 18 (7) 19 (8)
20 (9) 21 (10) 22 (11) 23 (12) 24 (13) 25 (14) 26 (15)
27 (16) 28 (17) 29 (18)        

 

Sivan

Her next menses begin 28 days later, on 10 Sivan during the day.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
      1 (19) 2 (20) 3 (21) 4 (22)
5 (23) 6 (24) 7 (25) 8 (26) 9 (27) 10 (28=1)
  
11 (2)
12 (3) 13 (4) 14 (5) 15 (6) 16 (7) 17 (8) 18 (9)
19 (10) 20 (11) 21 (12) 22 (13) 23 (14) 24 (15) 25 (16)
26 (17) 27 (18) 28 (19) 29 (20) 30 (21)    

 

Tammuz

Her next menses begin 28 days later, on 7 Tammuz during the day.

She has now menstruated at 28-day intervals, beginning during the day, for three consecutive months. She has established a veset kavua for the haflagah.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
          1 (22) 2 (23)
3 (24) 4 (25) 5 (26) 6 (27) 7 (28=1)
  
8 (1) 9 (2)
10 (3) 11 (4) 12 (5) 13 (6) 14 (7) 15 (8) 16 (9)
17 (10) 18 (11) 19 (12) 20 (13) 21 (14) 22 (15) 23 (16)
24 (17) 25 (18) 26 (20) 27 (21) 28 (22) 29 (23)  

 

Av

She observes her veset kavua after a 28-day interval, on 5 Av.

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
            1 (24)
2 (25) 3 (26) 4 (27) 5 (28)   6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30            
 

 

Uprooting a Veset Kavua: Graphic Calendars

A woman establishes a veset kavua (established veset) if her cycle follows a consistent and predictable pattern for three consecutive cycles. If on three consecutive occasions the date of the veset kavua passes with no bleeding, then the veset kavua is "uprooted" and she no longer anticipates it.

If a woman has established a veset kavua, but one month, her menstruation begins on a different day, she continues to observe her veset kavua the following month .  She also observes yom hachodesh (the day of the Hebrew month) and the haflagah (interval) based on her most recent menses, but she does not observe onah beinonit (the average onah).

For example, a woman has a veset kavua for the 15th day of the month. But her menses begin only on the 18th day of Nissan. In Iyar, she will observe:

  1. The 15th of Iyar, which is her veset kavua.
  2. The 18th of Iyar, which is the yom hachodesh from her actual menses.
  3. The 20th of Iyar. This is a 33-day interval after the 18th of Nissan. The interval between her two previous menstrual periods, on the 15th of Adar and the 18th of Nissan, was 33 days.

Adar

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
            1
2 3 4 5 6 7 8
9 10 11 12 13 14 15   
    Kavua
16 17 18 19 20 21 22
23 24 25 26 27 29 29

 

Nissan

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15     16 17 18    19  20  21 
22  23 24 25 26 27 28
29 30          

 

Iyar

Rishon Sheini Shlishi Revi'i Chamishi Shishi Shabbat
    1 2 3 4 5
6 7 8 9 10 11 12
13 14 15    16 17 18    19
20    21 22 23 24 25 26
27 28 29        


If on three consecutive occasions the date of the veset kavua passes with no bleeding, then the veset kavua is "uprooted" and she no longer observes it. From that point on, she has a veset she'eino kavua and observes yom hachodesh, the haflagah, and the onah beinonit.

 

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