Neat Excel Trick to create dates table

[spl]

It is often helpful when working with data involving dates to have a lookup table to more describe a 'date', i.e. day of week, is it a weekend, what quarter... etc.

Excel's Power Query [mCode] can quickly create a spreadsheet table for a date range. If you have Excel and want to see how this works continue reading

Steps:

• Open a Blank Excel file
• Click on Data; New Query; From other source; blank query
• Click on Advanced Editor

At that point the editor will have a basic let...in - delete the text, then insert

Code Select Expand

let
    Today = Date.From( DateTime.LocalNow() ),
    StartDate = #date(2000, 1, 1),
    EndDate = #date(2024, 12, 31),
    #"List of Dates" = List.Dates( StartDate, Duration.Days( EndDate - StartDate ) +1, #duration( 1, 0, 0, 0 ) ),
    #"Converted to Table" = Table.FromList( #"List of Dates", Splitter.SplitByNothing(), type table[Date = Date.Type] ),
    #"Insert Date Integer" = Table.AddColumn(#"Converted to Table", "Date Integer", each Number.From( Date.ToText( [Date], "yyyyMMdd" ) ), Int64.Type ),
    #"Insert Year" = Table.AddColumn(#"Insert Date Integer", "Year", each Date.Year([Date]), Int64.Type),
    // Creates a dynamic year value called 'Current' that moves with the current date. Put this value in a slicer and it automatically switches to the Current period.
    #"Add Year Default" = Table.AddColumn(#"Insert Year", "Year Default", each if Date.Year( Today ) = [Year] then "Current" else Text.From( [Year] ), type text),
    #"Insert YYYY-MM" = Table.AddColumn(#"Add Year Default", "YYYY-MM", each Date.ToText( [Date], "yyyy-MM"), type text),
    #"Insert Month-Year" = Table.AddColumn(#"Insert YYYY-MM", "Month-Year", each Date.ToText( [Date], "MMM yyyy"), type text),
    #"Insert Month Number" = Table.AddColumn(#"Insert Month-Year", "Month Of Year", each Date.Month([Date]), Int64.Type),
    #"Insert Month Name" = Table.AddColumn(#"Insert Month Number", "Month Name", each Date.MonthName([Date], "EN-us"), type text),
    #"Insert Month Name Short" = Table.AddColumn(#"Insert Month Name", "Month Name Short", each Date.ToText( [Date] , "MMM", "EN-us" ), type text),
    // Creates a dynamic year value called 'Current' that moves with the current date. Put this value in a slicer and it automatically switches to the current period.
    #"Add Month Name Default" = Table.AddColumn(#"Insert Month Name Short", "Month Name Default", each if Date.Month( Today ) = [Month Of Year] then "Current" else [Month Name], type text ),
    #"Insert Start of Month" = Table.AddColumn(#"Add Month Name Default", "Start of Month", each Date.StartOfMonth([Date]), type date),
    #"Inserted End of Month" = Table.AddColumn(#"Insert Start of Month", "End of Month", each Date.EndOfMonth( [Date] ), type date),
    #"Inserted Days in Month" = Table.AddColumn(#"Inserted End of Month", "Days in Month", each Date.DaysInMonth([Date]), Int64.Type),
    #"Add ISO Week" = Table.AddColumn(#"Inserted Days in Month", "ISO Weeknumber", each let
   CurrentThursday = Date.AddDays([Date], 3 - Date.DayOfWeek([Date], Day.Monday ) ),
   YearCurrThursday = Date.Year( CurrentThursday ),
   FirstThursdayOfYear = Date.AddDays(#date( YearCurrThursday,1,7),- Date.DayOfWeek(#date(YearCurrThursday,1,1), Day.Friday) ),
   ISO_Week = Duration.Days( CurrentThursday - FirstThursdayOfYear) / 7 + 1
in ISO_Week, Int64.Type ),
    #"Add ISO Year" = Table.AddColumn(#"Add ISO Week", "ISO Year", each Date.Year(  Date.AddDays( [Date], 26 - [ISO Weeknumber] ) ), Int64.Type ),
    #"Insert Start of Week" = Table.AddColumn(#"Add ISO Year", "Start of Week", each Date.StartOfWeek([Date], Day.Monday ), type date),
    #"Insert Quarter Number" = Table.AddColumn(#"Insert Start of Week", "Quarter Number", each Date.QuarterOfYear([Date]), Int64.Type),
    #"Added Quarter" = Table.AddColumn(#"Insert Quarter Number", "Quarter", each "Q" & Text.From( Date.QuarterOfYear([Date]) ), type text ),
    #"Add Year-Quarter" = Table.AddColumn(#"Added Quarter", "Year-Quarter", each Text.From( Date.Year([Date]) ) & "-Q" & Text.From( Date.QuarterOfYear([Date]) ), type text ),
    #"Insert Day Name" = Table.AddColumn(#"Add Year-Quarter", "Day Name", each Date.DayOfWeekName([Date], "EN-us" ), type text),
    #"Insert Day Name Short" = Table.AddColumn( #"Insert Day Name", "Day Name Short", each Date.ToText( [Date], "ddd", "EN-us" ), type text),
    #"Insert Day of Month Number" = Table.AddColumn(#"Insert Day Name Short", "Day of Month Number", each Date.Day([Date]), Int64.Type),
    // Day.Monday indicates the week starts on Monday. Change this in case you want the week to start on a different date.
    #"Insert Day of Week" = Table.AddColumn(#"Insert Day of Month Number", "Day of Week Number", each Date.DayOfWeek( [Date], Day.Monday ), Int64.Type),
    #"Insert Day of Year" = Table.AddColumn(#"Insert Day of Week", "Day of Year Number", each Date.DayOfYear( [Date] ), Int64.Type),
    #"Add Day Offset" = Table.AddColumn(#"Insert Day of Year", "Day Offset", each Number.From( Date.From( Today ) - [Date] ) , Int64.Type ),
    #"Add Week Offset" = Table.AddColumn(#"Add Day Offset", "Week Offset", each Duration.Days( Date.StartOfWeek( [Date], Day.Monday ) - Date.StartOfWeek( Today, Day.Monday ) ) / 7 , Int64.Type ),
    #"Add Month Offset" = Table.AddColumn(#"Add Week Offset", "Month Offset", each ( [Year] - Date.Year( Today ) ) * 12 + ( [Month Of Year] - Date.Month( Today ) ), Int64.Type ),
    #"Add Quarter Offset" = Table.AddColumn(#"Add Month Offset", "Quarter Offset", each ( [Year] - Date.Year(Today) ) * 4 + Date.QuarterOfYear( [Date] ) - Date.QuarterOfYear( Today ), Int64.Type ),
    #"Add Year Offset" = Table.AddColumn(#"Add Quarter Offset", "Year Offset", each [Year] - Date.Year(Today), Int64.Type ),
    #"Insert Is Weekend" = Table.AddColumn(#"Add Year Offset", "Is Weekend", each if Date.DayOfWeek( [Date] ) >= 5 then 1 else 0, Int64.Type ),
    #"Insert Is Weekday" = Table.AddColumn(#"Insert Is Weekend", "Is Weekday", each if Date.DayOfWeek( [Date] ) < 5 then 1 else 0, Int64.Type )
in
    #"Insert Is Weekday"

You should see the input was accepted with no errors. The code above has a date range from 1/1/2000 but you can change the range with dates on your choice. Click Close and Load and sheet2 will have your table with columns fully describing each data. You can choose to save the workbook and import the table into a database as a lookup; export as csv and use that to create a SQLite table, or just close w/out saving but keep mCode in your back pocket.