How To Calculate Age in Days, Hours and Minutes in SQL Server Transact-SQL?

On many Web sites, news items or blog articles are displayed with a publishing data and time represented in days, hours and minutes. To do this you can use the DATEDIFF() function with a simple algorithm as shown in the tutorial exercise below:

-- Age in days
DECLARE @submit_date DATETIME;
SET @submit_date = '2007-05-11 16:10:41.403';
SELECT 'Posted '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(day, @submit_date, GETDATE()))
   + ' days ago.';
GO
Posted 8 days ago.

-- Age in days, hours and minutes - Wrong
DECLARE @submit_date DATETIME;
SET @submit_date = '2007-05-11 16:10:41.403';
SELECT 'Posted '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(day, @submit_date, GETDATE()))
   + ' days, '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(hour, @submit_date, GETDATE()))
   + ' hours, and '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(minute, @submit_date, GETDATE()))
   + ' minutes ago.';
GO
Posted 7 days, 186 hours, and 11202 minutes ago.

-- Age in days, hours and minutes - Correct
DECLARE @submit_date DATETIME;
SET @submit_date = '2007-05-11 16:10:41.403';
SELECT 'Posted '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(minute, @submit_date, GETDATE())/(24*60))
   + ' days, '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(minute, @submit_date, GETDATE())%(24*60)/60)
   + ' hours, and '
   + CONVERT(VARCHAR(40), 
      DATEDIFF(minute, @submit_date, GETDATE())%60)
   + ' minutes ago.';
GO
Posted 7 days, 18 hours, and 42 minutes ago.

Notice how the correct number of days, hours, and minutes are calculated using the concepts of whole day, remaining partial day, whole hour, and remaining partial hour as shown below:

|...................|...................|...+...+..

|<------- number of whole days -------->|<------->|
                    remaining partial day ---^

|<----------- number of whole hours ----------->|-|
                       remaining partial hour ---^

|<----------- total number of minutes ----------->|

• Number of whole days: DATEDIFF(minute, @submit_date, GETDATE())/(24*60), where 24*60 is the number of minutes in a whole day.
• Number of minutes in the remaining partial day: DATEDIFF(minute, @submit_date, GETDATE())%(24*60).
• Number of minutes in the remaining partial hour: DATEDIFF(minute, @submit_date, GETDATE())%60.

 

⇒Date/Time Operations and Functions in SQL Server Transact-SQL

⇒⇒SQL Server Transact-SQL Tutorials