weekOfMonth

Syntax

weekOfMonth(X, [week=0], [weekday=0], [offset], [n=1])

Arguments

X is a scalar/vector of type DATE, DATETIME, TIMESTAMP or NANOTIMESTAMP.

week (optional) is an integer from 0 to 3 indicating the i-th week of a month. The default value is 0.

weekday (optional) is an integer from 0 to 6. 0 means Monday, 1 means Tuesday, ..., and 6 means Sunday. The default value is 0.

offset (optional) is a scalar of the same data type as X. It must be no greater than the minimum value of X. The default value is the minimum value of X.

n (optional) is a positive integer. The default value is 1.

Details

In the calendar month of X, suppose the "week"-th "weekday" is d.

  • If X<d: return the week-th "weekday" in the previous calendar month.

  • If X>=d: return the week-th "weekday" in the current calendar month.

If parameter offset is specified, the result is updated every n months. Parameter offset works only if parameter n>1.

Examples

weekOfMonth(2019.11.01,2,4);
// output
2019.10.18

weekOfMonth(2019.11.20,2,4);
2019.11.15

date=2012.01.02 2012.02.03 2012.03.07 2012.04.08 2012.05.12 2012.06.16 2012.07.18 2012.08.20 2012.09.25 2012.10.28
time = [09:34:07,09:36:42,09:36:51,09:36:59,09:32:47,09:35:26,09:34:16,09:34:26,09:38:12,09:38:13]
sym = take(`MSFT,10)
price= 49.6 29.46 29.52 30.02 174.97 175.23 50.76 50.32 51.29 52.38
qty = 2200 1900 2100 3200 6800 5400 1300 2500 8800 4500
t1 = table(date, time, sym, qty, price);

select avg(price),sum(qty) from t1 group by weekOfMonth(date,3,4,2012.01.01,2);
weekOfMonth_date avg_price sum_qty
2011.12.23 39.53 4100
2012.02.24 29.77 5300
2012.04.27 175.1 12200
2012.06.22 50.54 3800
2012.08.24 51.29 8800
2012.10.26 52.38 4500