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Navigation: Appendices

Week Number Recurrence Rules Values

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Although week numbers are never used in worldwide public holidays, it is possible to construct a recurring holiday rule that is based on week numbers, and this is sometimes used to specify the date of an insertion.

 

The fixed date recurrence rule for the weekday of a given week number is:

 

((7*(w-1))+(D-1)-3) days after the Thursday on or after January 1

 

where W is the week number and D is the weekday (running from 1-7 for Monday to Sunday).

 

For your convenience, the value of ((7*(w-1))+(D-1)-3) (the offset) has been calculated for the Monday (D=1) of all week numbers from 1 to 52.

 

Week

Offset

 

Week

Offset

 

Week

Offset

 

Week

Offset

1

-3*

 

14

88

 

27

179

 

40

270

2

4

 

15

95

 

28

186

 

41

277

3

11

 

16

102

 

29

193

 

42

284

4

18

 

17

109

 

30

200

 

43

291

5

25

 

18

116

 

31

207

 

44

298

6

32

 

19

123

 

32

214

 

45

305

7

39

 

20

130

 

33

221

 

46

312

8

46

 

21

137

 

34

228

 

47

319

9

53

 

22

144

 

35

235

 

48

326

10

60

 

23

151

 

36

242

 

49

333

11

67

 

24

158

 

37

249

 

50

340

12

74

 

25

165

 

38

256

 

51

347

13

81

 

26

172

 

39

263

 

52

354

 

* note that if the offset value is negative, then the rule above should change from "days after" to "days before".

 


Topic 186610, last updated on 24-Apr-2022