Duration.From Function in Power Query M (5 Easy Examples)

Duration.From converts a value into a duration, taking a number of days, a d.h:m:s text string, or an existing duration and giving you back a duration value. Available in Excel (Power Query), Power BI Desktop, and Power BI Service.

If you have a decimal number of days or an elapsed-time string and you want Power Query to treat it as a real duration, this is the function you reach for.

Table of Contents

Syntax of Duration.From Function

Duration.From(value as any) as nullable duration

where

value (required, any). The value to convert into a duration. It can be a number (read as a count of days), a text string in d.h:m:s form, an existing duration, or null.

Returns: a duration value. If value is null, it returns null.

In plain terms, you give it a number, some text, or a duration, and it hands back a proper duration value you can do duration math with.

Example 1: Convert a number of days to a duration

A number is read as a count of days, so 2.525 means just over two and a half days.

Duration.From(2.525)

Result: 2.12:36:00

The fractional part becomes hours, minutes, and seconds, so 2.525 days is 2 days, 12 hours, and 36 minutes.

Example 2: Convert a text string to a duration

Text has to be in d.h:m:s form, with a dot before the day part and colons between the time parts.

Duration.From("3.06:30:00")

Result: 3.06:30:00

The string parses to 3 days, 6 hours, and 30 minutes.

Example 3: Get the total hours from a duration

A bare duration is hard to use in a calculation, much like the duration you get from a date difference in Power Query, so wrap it in Duration.TotalHours to get a single number.

Duration.TotalHours(Duration.From(2.525))

Result: 60.6

2.525 days is 60.6 hours in total, which is the whole span expressed in hours.

Example 4: Get the hours component from a duration

Duration.Hours pulls just the hours part, not the total.

Duration.Hours(Duration.From(2.525))

Result: 12

This returns 12, the hours component of 2.12:36:00, not the 60.6 total hours from Example 3.

Example 5: Convert a column of decimal days to total hours

The most common real use is turning a whole column of decimal-day values into a usable number.

Say you have a Shifts query with a Task and a DecimalDays column.

You want a new column showing each shift’s total hours.

Here is the starting data:

Task	DecimalDays
REF-451	0.5
REF-452	1.25
REF-453	2.525

Now add a column that runs Duration.From on each value and totals the hours:

let
    Source = Excel.CurrentWorkbook(){[Name="Shifts"]}[Content],
    AddHours = Table.AddColumn(Source,"TotalHours",each Duration.TotalHours(Duration.From([DecimalDays])),type number)
in
    AddHours

This converts each decimal-day value to a duration, then reads it back as a number of hours.

The result has the new TotalHours column:

Task	DecimalDays	TotalHours
REF-451	0.5	12
REF-452	1.25	30
REF-453	2.525	60.6

Each value is read as days first, so 0.5 becomes 12 hours, 1.25 becomes 30 hours, and 2.525 becomes 60.6 hours.

Things to keep in mind with Duration.From

A number is read as DAYS, not hours or seconds. Duration.From(1) is one whole day (1.00:00:00), not one hour. To convert from hours divide by 24, from minutes divide by 1440, from seconds divide by 86400.
Text must be in d.h:m:s form. The day part is separated by a dot and the time parts by colons, as in "2.05:55:20". A plain "05:55:20" with no day part is fine and parses as 0 days, but wrong separators throw an error.
null passes through as null. It does not error, which is handy inside Table.AddColumn over a column that may have blanks. Those rows simply get null.
It is different from the #duration(...) constructor. #duration(d,h,m,s) builds a duration from four explicit numbers and is the right tool when you already have the parts. Duration.From coerces a single value, so use it when you have one decimal-days number or a text string to convert.
It pairs with the Duration.Total* and component accessors. A raw duration is awkward to display or sum, so Duration.From is almost always followed by Duration.TotalHours and friends to get a single number, or by component accessors like Duration.Days and Duration.Hours to pull one part.

Common questions about Duration.From

Should I use Duration.From or #duration?

Use the #duration(d,h,m,s) constructor when you already have separate day, hour, minute, and second numbers. Use Duration.From when you have one decimal-days number or a d.h:m:s text string that needs converting.

How do I convert hours or minutes into a duration?

Divide by 24 for hours or 1440 for minutes first, because the number argument is read as days. For example, Duration.From(90/1440) gives 0.01:30:00, which is 90 minutes.

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