Dates = 
VAR StartDate = DATE(2015, 1, 1)
VAR EndDate = DATE(2031, 12, 31)
VAR FinancialYearStartMonth = 4
VAR TodayDate = TODAY()

--------------------------------
-- STEP 1: Base date table
--------------------------------
VAR BaseCalendar =
    ADDCOLUMNS (
        CALENDAR(StartDate, EndDate),

        // Base components
        "Year", YEAR([Date]),
        "Month Number", MONTH([Date]),
        "Month Name", FORMAT([Date], "MMMM"),
        "Month Short", FORMAT([Date], "MMM"),
        "Day", DAY([Date]),
        "Day of Year", DATEDIFF(DATE(YEAR([Date]), 1, 1), [Date], DAY) + 1,

        // Week-based logic
        "Week Number", WEEKNUM([Date], 2),
        
        // ISO Week Number
        "ISO Week Number",
            VAR jan4 = DATE(YEAR([Date]), 1, 4)
            VAR jan4Weekday = WEEKDAY(jan4, 2)
            VAR firstThursday = jan4 - jan4Weekday + 4
            RETURN INT(( [Date] - firstThursday + 10 ) / 7),

        "Weekday Number", WEEKDAY([Date], 2),
        "Weekday Name", FORMAT([Date], "dddd"),
        "Weekday Short", FORMAT([Date], "ddd"),
        "Is Weekend", IF(WEEKDAY([Date], 2) > 5, TRUE(), FALSE()),

        // Quarters and sort keys
        "Quarter", "Q" & FORMAT([Date], "Q"),
        "Quarter Number", QUARTER([Date]),
        "Month Year", FORMAT([Date], "MMM YYYY"),
        "Year-Month", FORMAT([Date], "YYYY-MM"),

        // Start/end of periods
        "Start of Month", DATE(YEAR([Date]), MONTH([Date]), 1),
        "End of Month", EOMONTH([Date], 0),
        "Start of Week", [Date] - WEEKDAY([Date], 2) + 1,
        "End of Week", [Date] + (7 - WEEKDAY([Date], 2)),

        // Season (UK Meteorological)
        "Season", 
            SWITCH (TRUE(),
                MONTH([Date]) IN {3, 4, 5}, "Spring",
                MONTH([Date]) IN {6, 7, 8}, "Summer",
                MONTH([Date]) IN {9, 10, 11}, "Autumn",
                "Winter"
            ),

        // Financial Year Number
        "Financial Year Number",
            VAR m = MONTH([Date])
            VAR y = YEAR([Date])
            RETURN IF(m >= FinancialYearStartMonth, y, y - 1),

        // Financial Year text format
        "Financial Year",
            VAR m = MONTH([Date])
            VAR y = YEAR([Date])
            RETURN IF(m >= FinancialYearStartMonth,
                FORMAT(y, "0000") & "/" & FORMAT(y + 1, "0000"),
                FORMAT(y - 1, "0000") & "/" & FORMAT(y, "0000")
            ),

        // Financial Month
        "Financial Month", MOD(MONTH([Date]) - FinancialYearStartMonth + 12, 12) + 1,

        // Financial Quarter
        "Financial Quarter",
            VAR fMonth = MOD(MONTH([Date]) - FinancialYearStartMonth + 12, 12) + 1
            RETURN "Q" & INT((fMonth + 2) / 3),

        // Week of Month
        "Week of Month", INT((DAY([Date]) - 1) / 7) + 1,

        // Sorting helpers
        "Month Sort", MONTH([Date]),
        "Day of Week Sort", WEEKDAY([Date], 2),
        "Quarter Sort", QUARTER([Date])
    )

--------------------------------
-- STEP 2: Dependent columns + Relative logic
--------------------------------
VAR FinalTable =
    ADDCOLUMNS (
        BaseCalendar,

        // Financial Week Number
        "Financial Week Number",
            VAR fyStart =
                IF(
                    MONTH([Date]) >= FinancialYearStartMonth,
                    DATE(YEAR([Date]), FinancialYearStartMonth, 1),
                    DATE(YEAR([Date]) - 1, FinancialYearStartMonth, 1)
                )
            RETURN DATEDIFF(fyStart, [Date], WEEK) + 1,

        // Current flags
        "Is Today", IF([Date] = TodayDate, TRUE(), FALSE()),
        "Is Current Month", IF(YEAR([Date]) = YEAR(TodayDate) && MONTH([Date]) = MONTH(TodayDate), TRUE(), FALSE()),
        "Is Current Year", IF(YEAR([Date]) = YEAR(TodayDate), TRUE(), FALSE()),
        "Is Current Financial Year",
            VAR CurrentFY = IF(MONTH(TodayDate) >= FinancialYearStartMonth, YEAR(TodayDate), YEAR(TodayDate) - 1)
            RETURN [Financial Year Number] = CurrentFY,

        --------------------------------
        -- Relative Period Flags
        --------------------------------
        "Relative Days",
            SWITCH(TRUE(),
                [Date] = TodayDate, "Today",
                [Date] = TodayDate - 1, "Yesterday",
                [Date] = TodayDate + 1, "Tomorrow",
                [Date] >= TodayDate - 7 && [Date] < TodayDate, "Last 7 Days",
                [Date] > TodayDate && [Date] <= TodayDate + 7, "Next 7 Days",
                BLANK()
            ),

        "Relative Months",
            SWITCH(TRUE(),
                YEAR([Date]) = YEAR(TodayDate) && MONTH([Date]) = MONTH(TodayDate), "Current Month",
                EOMONTH([Date], 0) = EOMONTH(TodayDate, -1), "Last Month",
                EOMONTH([Date], 0) = EOMONTH(TodayDate, 1), "Next Month",
                BLANK()
            ),

        "Relative Quarters",
            VAR CurrQtr = QUARTER(TodayDate)
            VAR CurrYr = YEAR(TodayDate)
            VAR RowQtr = QUARTER([Date])
            VAR RowYr = YEAR([Date])
            RETURN
                SWITCH(TRUE(),
                    RowYr = CurrYr && RowQtr = CurrQtr, "Current Quarter",
                    (RowYr = CurrYr && RowQtr = CurrQtr - 1) || (RowYr = CurrYr - 1 && CurrQtr = 1 && RowQtr = 4), "Last Quarter",
                    (RowYr = CurrYr && RowQtr = CurrQtr + 1) || (RowYr = CurrYr + 1 && CurrQtr = 4 && RowQtr = 1), "Next Quarter",
                    BLANK()
                ),

        "Relative Years",
            SWITCH(TRUE(),
                YEAR([Date]) = YEAR(TodayDate), "Current Year",
                YEAR([Date]) = YEAR(TodayDate) - 1, "Last Year",
                YEAR([Date]) = YEAR(TodayDate) + 1, "Next Year",
                BLANK()
            ),

        --------------------------------
        -- Rolling Period Flags
        --------------------------------
        "Rolling Period",
            SWITCH(TRUE(),
                [Date] >= TodayDate - 30 && [Date] <= TodayDate, "Last 30 Days",
                [Date] >= TodayDate - 90 && [Date] <= TodayDate, "Last 90 Days",
                [Date] >= EDATE(TodayDate, -12) && [Date] <= TodayDate, "Last 12 Months",
                BLANK()
            ),

        --------------------------------
        -- Relative Indexes (Numeric)
        --------------------------------
        // Days difference from today
        "Relative Day Index", DATEDIFF(TodayDate, [Date], DAY),

        // Months difference from current month
        "Relative Month Index",
            (YEAR([Date]) - YEAR(TodayDate)) * 12 + (MONTH([Date]) - MONTH(TodayDate)),

        // Quarters difference from current quarter
        "Relative Quarter Index",
            ((YEAR([Date]) - YEAR(TodayDate)) * 4) + (QUARTER([Date]) - QUARTER(TodayDate)),

        // Years difference from current year
        "Relative Year Index", YEAR([Date]) - YEAR(TodayDate)
    )

RETURN
    FinalTable