lastWeekOfMonth

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

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

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

offset 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 is a positive integer. The default value is 1.

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

lastWeekOfMonth(2019.11.24,2);
// output
2019.10.30
// The last Wednesday of November 2019 is 2019.11.27, 2019.11.24 is before 2019.11.27, so the function returns the last Wednesday of October 2019.

lastWeekOfMonth(2019.11.29,2);
// output
2019.11.27

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 lastWeekOfMonth(date,4,2012.01.01,2);