How to “auto” generate calendar tables with Power Query – The best method

Share

Facebook
Twitter
LinkedIn
automatic calendar table with power query

Calendar (or date) table is crucial for performing date intelligence calculations in Power BI. 

Normally, you would find a reasonable calendar table in most data models. But occasionally I come across models where there is no calendar table. 

So I present to you, the ultimate & best way to generate calendar table using Power Query.

How to create the perfect calendar table with Power Query?

Start by creating a new “blank query” connection in Power BI.

blank query option in Power BI (PQ)

Then use the =List.Dates() function to generate the dates you want.

For example, to get the calendar dates for year 2025 use below code:

				
					= List.Dates(#date(2025,1,1),365, #duration(1,0,0,0))
				
			

This will generate a list of all the dates in 2025. 

Now, convert the list to a table using the List Tools > Transform ribbon. 

convert list of dates to a table

Once you have the dates in a table format, you can use the “add column” ribbon and “Date” options to introduce many date related columns.

For example you can add:

  • Year (4 digit year value)
  • Month number
  • Month name
  • Weekday name
  • Weekday number
  • Start of month
  • End of month
  • Start of week
  • Quarter of the year
  • Days in a month
Adding date calculations with Power Query

Additional "smart" date columns

Apart from all the columns above, I normally add these two columns to my calendar tables.

  • Year month (a 6 digit representation like 202308 for ex.)
  • Type of month (current month, previous month, next month)

Let’s look at the Power Query (M) code for these columns.

Year Month (yyyymm):

 

				
					= Table.AddColumn(#"Inserted Start of Month", "Year Month", each [Year] * 100 + [Month])
				
			

Type of Month:

For this we need to do use conditional logic and isinmonth functions of M. Here is the M code for tagging dates as “previous month”, “this month” and “next month”
				
					= Table.AddColumn(#"Added Custom", "Month Type", each if Date.IsInCurrentMonth([Date]) then "This Month"
else if Date.IsInPreviousMonth([Date]) then "Previous Month" 
else if Date.IsInNextMonth([Date]) then "Next Month" 
else "Other Month")
				
			

Full M Script for generating the 2025 calendar table

Use this M script to generate the calendar table for year 2025. 

To apply this, create a blank query in PQ and then go to View > Advanced Editor and paste the code there. Adjust the year in source step (step 1) to get the calendar for any year.

				
					let
    Source = List.Dates(#date(2025,1,1),365, #duration(1,0,0,0)),
    #"Converted to Table" = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
    #"Renamed Columns" = Table.RenameColumns(#"Converted to Table",{{"Column1", "Date"}}),
    #"Changed Type" = Table.TransformColumnTypes(#"Renamed Columns",{{"Date", type date}}),
    #"Inserted Year" = Table.AddColumn(#"Changed Type", "Year", each Date.Year([Date]), Int64.Type),
    #"Inserted Month" = Table.AddColumn(#"Inserted Year", "Month", each Date.Month([Date]), Int64.Type),
    #"Inserted Month Name" = Table.AddColumn(#"Inserted Month", "Month Name", each Date.MonthName([Date]), type text),
    #"Inserted Day of Week" = Table.AddColumn(#"Inserted Month Name", "Day of Week", each Date.DayOfWeek([Date]), Int64.Type),
    #"Inserted Day Name" = Table.AddColumn(#"Inserted Day of Week", "Day Name", each Date.DayOfWeekName([Date]), type text),
    #"Added Conditional Column" = Table.AddColumn(#"Inserted Day Name", "Is Weekend?", each if [Day of Week] = 6 then "Yes" else if [Day of Week] = 0 then "Yes" else "No"),
    #"Inserted Start of Month" = Table.AddColumn(#"Added Conditional Column", "Start of Month", each Date.StartOfMonth([Date]), type date),
    #"Added Custom" = Table.AddColumn(#"Inserted Start of Month", "Year Month", each [Year] * 100 + [Month]),
    #"Added Custom1" = Table.AddColumn(#"Added Custom", "Month Type", each if Date.IsInCurrentMonth([Date]) then "This Month"
else if Date.IsInPreviousMonth([Date]) then "Previous Month" 
else if Date.IsInNextMonth([Date]) then "Next Month" 
else "Other Month")
in
    #"Added Custom1"
				
			

Perfect Calendar with Power Query - Video

Check out this video to understand the process better.

How to customize the Calendar Query for other years?

You can change the “Source” step and replace the year number or number of days to generate the calendar for whatever year you need. For example, to make the 2 years calendar for years 2026 and 2027, use this code:

				
					= List.Dates(#date(2026,1,1),730, #duration(1,0,0,0))
				
			

To make the calendar for next “n” years:

We can use additional date functions in Power Query M language to generate the calendar for next “n” years from a start date. For example, if you change the source step to below code, you will get next 5 years calendar from 1-Jan-2025.

				
					= let start_date = #date(2025,1,1), number_of_years = 5, end_date = Date.AddYears(start_date,number_of_years), total_days = Duration.Days(end_date - start_date)
in List.Dates(start_date,total_days, #duration(1,0,0,0))
				
			

More ways to make the calendar table

Check out below tutorials from other Power BI / Excel folks to see different Power Query scripts.

Facebook
Twitter
LinkedIn

Share this tip with your colleagues

Excel and Power BI tips - Chandoo.org Newsletter

Get FREE Excel + Power BI Tips

Simple, fun and useful emails, once per week.

Learn & be awesome.

Welcome to Chandoo.org

Thank you so much for visiting. My aim is to make you awesome in Excel & Power BI. I do this by sharing videos, tips, examples and downloads on this website. There are more than 1,000 pages with all things Excel, Power BI, Dashboards & VBA here. Go ahead and spend few minutes to be AWESOME.

Read my storyFREE Excel tips book

Overall I learned a lot and I thought you did a great job of explaining how to do things. This will definitely elevate my reporting in the future.
Rebekah S
Reporting Analyst
Excel formula list - 100+ examples and howto guide for you

From simple to complex, there is a formula for every occasion. Check out the list now.

Calendars, invoices, trackers and much more. All free, fun and fantastic.

Advanced Pivot Table tricks

Power Query, Data model, DAX, Filters, Slicers, Conditional formats and beautiful charts. It's all here.

Still on fence about Power BI? In this getting started guide, learn what is Power BI, how to get it and how to create your first report from scratch.

13 Responses to “Convert fractional Excel time to hours & minutes [Quick tip]”

  1. Debraj Roy says:

    Hi Purna..

    Again a great tip.. Its a great way to convert Fractional Time..
    By the way.. Excel has two great and rarely used formula..

    =DOLLARFR(7.8,60) and =DOLLARDE(7.48,60)

    basically US Account person uses those to convert some currency denomination.. and we can use it to convert Year(i.e 3.11 Year = 3 year 11 month) and Week(6.5 week = 6 week 5 days), in the same manner...

  2. Jason says:

    This doesn't work for me. When applying the custom format of [h]:mm to 7.8 I get 187:12

    Any ideas why?

    • Hui... says:

      @Jason
      7.8 in Excel talk means 7.8 days
      =7.8*24
      =187.2 Hrs
      =187 Hrs 12 Mins

      If you follow Chandoo's instructions you will see that he divides the 7.8 by 24 to get it to a fraction of a day

      Simple, assuming the fractional time is in cell A1,

      Use below steps to convert it to hours & minutes:

      1. In the target cell, write =A1/24
      2. Select the target cell and press CTRL+1 to format it (you can also right click and select format cells)
      3. Select Custom from “Number” tab and enter the code [h]:mm
      4. Done!

  3. WhoKnows says:

    Hi, sorry to point this out but Column C Header is misspelt 'Hours Palyed'

  4. abhishek malik says:

    good one

  5. Julia says:

    So how do I go the other way and get hours and minutes to fractional time?

    • Chandoo says:

      If you have 7.5 in cell A1,

      - Use int(A1) to get the hours.
      - Use mod(A1,1)*60 to get minutes.

      If you have 7:30 (formatted as time) in A1

      - Use hours(a1) to get hours
      - Use minutes(a1) to get minutes.

      • Paula says:

        I had the same issue. You can solve it by changing the format as described above:

        Right click cell > Format Cells > (In Number tab) > Custom > Then enter the code [h]:mm
        ([hh]:mm and [hhh]:mm are nice too if you want to show leading zeros)

        • Jack Scarce says:

          Thanks guys, these are the tips I'm looking for.
          ...dividing the number of minutes elapsed by the percent change is my task - "int" is the key this time

  6. Srikanth says:

    It doesnt work for greater than 24 hours
    It returns 1:30 for 25.5 hours. It should have returned 25:30

    Ideally I would right function as
    =QUOTIENT(A1,1)&":"&MOD(A1,1)*60

    • Paula says:

      Sorry, replied to wrong comment....

      ----
      I had the same issue. You can solve it by changing the format as described above:

      Right click cell > Format Cells > (In Number tab) > Custom > Then enter the code [h]:mm
      ([hh]:mm and [hhh]:mm are nice too if you want to show leading zeros)

  7. Daniel says:

    Clever use of MOD here to extract the decimal part of a number. Divide a number containing a decimal by 1 and return the remainder. Humm. Very clever.

  8. Tomer says:

    Thanks very much, extremely useful !

Leave a Reply