Date & Time functions

DAYS_IN_MONTH

About

Calculates the number of days from a particular time period, that occur within a particular month.

Inputs:

• start_date : start date of time period
• end_date : end date of time period
• eom_dates : a horizontal vector of month end dates

Code

DAYS_IN_MONTH = LAMBDA(start_date, end_date, eom_dates,
    LET(
        som_dates, DATE(YEAR(eom_dates), MONTH(eom_dates), 1),
        min_end_date, BYCOL(eom_dates, LAMBDA(x, MIN(x, end_date))),
        max_start_date, BYCOL(som_dates, LAMBDA(x, MAX(x, start_date))),
        days_in_month, BYCOL(min_end_date - max_start_date + 1, LAMBDA(x, MAX(x, 0))),
        days_in_month
    )
);