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DATEDIF Function

Calculates the difference between two valid date values for the specified units of measure.

  • Inputs must be column references.

  • The first value is used as the baseline to compare the date values.

  • Results are calculated to the integer value that is closest to and lower than the exact total; remaining decimal values are dropped.

Wrangle vs. SQL: This function is part of Wrangle, a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

Basic Usage

datedif(StartDate, EndDate, month)

Output: Returns the number of full months that have elapsed between StartDate and EndDate.

Syntax and Arguments

datedif(date1,date2,date_units)

Argument

Required?

Data Type

Description

date1

Y

datetime

Starting date to compare

date2

Y

datetime

Ending date to compare

date_units

Y

string

String literal representing the date units to use in the comparison

For more information on syntax standards, see Language Documentation Syntax Notes.

date1, date2

Date values to compare using the date_units units. If date2 > date1, then results are positive.

  • Date values must be column references.

  • If date1 and date2 have a specified time zone offset, the function calculates the difference including the timezone offsets.

  • If date1 does not have a specified time zone but date2 does, the function uses the local time in the same time zone as date2 to calculate the difference. The functions returns the difference without the time zone offset.

Usage Notes:

Required?

Data Type

Example Value

Yes

String (Date column reference)

LastContactDate

date_units

Unit of date measurement to calculate between the two valid dates.

Usage Notes:

Required?

Data Type

Example Value

Yes

String

year

Accepted Value for date units:

  • year

  • quarter

  • month

  • dayofyear

  • week

  • day

  • hour

  • minute

  • second

  • millisecond

Examples

Sugerencia

For additional examples, see Common Tasks.

Example - aged orders

This example illustrates how to calculate the number of days that have elapsed between the order date and today.

Function:

Item

Description

DATEDIF Function

Calculates the difference between two valid date values for the specified units of measure.

TODAY Function

Derives the value for the current date in UTC time zone. You can specify a different time zone by optional parameter.

IF Function

TheIFfunction allows you to build if/then/else conditional logic within your transforms.

Source:

For the orders in the following set, you want to charge interest for those ones that are older than 90 days.

OrderId

OrderDate

Amount

1001

1/31/16

1000

1002

11/15/15

1000

1003

12/18/15

1000

1004

1/15/16

1000

Transformation:

The first step is to create a column containing today's (03/03/16) date value:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

TODAY()

Parameter: New column name

'Today'

You can now use this value as the basis for computing the number of elapsed days for each invoice:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

DATEDIF(OrderDate, Today, day)

The age of each invoice in days is displayed in the new column. Now, you want to add a little bit of information to this comparison. Instead of just calculating the number of days, you could write out the action to undertake. Replace the above with the following:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

IF((DATEDIF(OrderDate, Today, day) > 90),'Charge interest','no action')

Parameter: New column name

'TakeAction'

To be fair to your customers, you might want to issue a notice at 45 days that the invoice is outstanding. You can replace the above with the following:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

IF(DATEDIF(OrderDate, Today, day) > 90,'Charge interest',IF(DATEDIF(OrderDate, Today, day) > 45),'Send letter','no action'))

Parameter: New column name

'TakeAction'

By using nested instances of the IF function, you can generate multiple results in the TakeAction column.

For the items that are over 90 days old, you want to charge 5% interest. You can do the following:

Transformation Name

Edit column with formula

Parameter: Columns

Amount

Parameter: Formula

IF(TakeAction == 'Charge interest',Amount * 1.05,Amount)

The above sets the value in the Amount column based on the conditional of whether the TakeAction column value is Charge interest. If so, apply 5% interest to the value in the Amount column.

Results:

OrderId

OrderDate

Amount

Today

TakeAction

1001

1/31/16

1000

03/03/16

no action

1002

11/15/15

1050

03/03/16

Charge interest

1003

12/18/15

1000

03/03/16

Send letter

1004

1/15/16

1000

03/03/16

Send letter

Example - dayofyear Calculations

This example demonstrates how dayofyear is calculated using the DATEDIF function, specifically how leap years and leap days are handled. Below, you can see some example dates. The year 2012 was a leap year.

Source:

dateId

d1

d2

Notes

1

1/1/10

10/10/10

Same year; no leap year

2

1/1/10

10/10/11

Different years; no leap year

3

10/10/11

1/1/10

Reverse dates of previous row

4

2/28/11

4/1/11

Same year; no leap year;

5

2/28/12

4/1/12

Same year; leap year; spans leap day

6

2/29/12

4/1/12

Same year; leap year; d1 = leap day

7

2/28/11

2/29/12

Diff years; d2 = leap day; converted to March 1 in d1 year

Transformation:

In this case, the transform is simple:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

datedif(d1,d2,dayofyear)

Parameter: New column name

'datedifs'

Results:

dateId

d1

d2

datedifs

Notes

1

1/1/10

10/10/10

282

Same year; no leap year

2

1/1/10

10/10/11

282

Different years; no leap year

3

10/10/11

1/1/10

-282

Reverse dates of previous row

4

2/28/11

4/1/11

32

Same year; no leap year;

5

2/28/12

4/1/12

33

Same year; leap year; spans leap day

6

2/29/12

4/1/12

32

Same year; leap year; d1 = leap day

7

2/28/11

2/29/12

1

Diff years; d2 = leap day; converted to March 1 in d1 year

Rows 1 - 3:

  • Row 1 provides the baseline calc.

  • In Row 2, the same days of the year are used, but the year is different by a count of 1. However, since we are computing dayofyear the result is the same as for Row 1.

    Nota

    When computing dayofyear, the year value for d2 is converted to the year of d1. The difference is then computed.

  • Row 3 represents the reversal of dates in Row 2.

    Nota

    Negative values for a dayofyear calculation indicate that d2 occurs earlier in the calendar than d1, ignoring year.

Rows 4 - 7: Leap years

  • Row 4 provides a baseline calculation for a non-leap year.

  • Row 5 uses the same days of year as Row 4, but the year (2012) is a leap year. Dates span a leap date (February 29). Note that the DATEDIF result is 1 more than the value in the previous row.

    Nota

    When the two dates span a leap date and the year for d1 is a leap year, then February 29 is included as part of the calculated result.

  • Row 6 moves date 1 forward by one day, so it is now on a leap day date. Result is one less than the previous row, which also spanned leap date.

  • Row 7 switches the leap date to d2. In this case, d2 is converted to the year of d1. However, since it was a leap day originally, in the year of d1, this value is March 1. Thus, the difference between the two dates is 1.

    Nota

    If d2 is a leap date and the year for d1 is not a leap year, the date used in for d2 is March 1 in the year of d1.