[.net] What is the correct SQL type to store a .Net Timespan with values > 24:00:00?

To be consistent with what is probably the most likely source of generating a time span (computing the difference of 2 times or date-times), you may want to store a .NET TimeSpan as a SQL Server DateTime Type.

This is because in SQL Server, the difference of 2 DateTime's (Cast to Float's and then Cast back to a DateTime) is simply a DateTime relative to Jan. 1, 1900. Ex. A difference of +0.1 second would be January 1, 1900 00:00:00.100 and -0.1 second would be Dec. 31, 1899 23:59:59.900.

To convert a .NET TimeSpan to a SQL Server DateTime Type, you would first convert it to a .NET DateTime Type by adding it to a DateTime of Jan. 1, 1900. Of course, when you read it into .NET from SQL Server, you would first read it into a .NET DateTime and then subtract Jan. 1, 1900 from it to convert it to a .NET TimeSpan.

For use cases where the time spans are being generated from SQL Server DateTime's and within SQL Server (i.e. via T-SQL) and SQL Server is prior to 2016, depending on your range and precision needs, it may not be practical to store them as milliseconds (not to mention Ticks) because the Int Type returned by DateDiff (vs. the BigInt from SS 2016+'s DateDiff_Big) overflows after ~24 days worth of milliseconds and ~67 yrs. of seconds. Whereas, this solution will handle time spans with precision down to 0.1 seconds and from -147 to +8,099 yrs..

WARNINGS:

  1. This would only work if the difference relative to Jan. 1, 1900 would result in a value within the range of a SQL Server DateTime Type (Jan. 1, 1753 to Dec. 31, 9999 aka -147 to +8,099 yrs.). We don't have to worry near as much on the .NET TimeSpan side, since it can hold ~29 k to +29 k yrs. I didn't mention the SQL Server DateTime2 Type (whose range, on the negative side, is much greater than SQL Server DateTime's), because: a) it cannot be converted to a numeric via a simple Cast and b) DateTime's range should suffice for the vast majority of use cases.

  2. SQL Server DateTime differences computed via the Cast - to - Float - and - back method does not appear to be accurate beyond 0.1 seconds.

Examples related to .net

You must add a reference to assembly 'netstandard, Version=2.0.0.0 How to use Bootstrap 4 in ASP.NET Core No authenticationScheme was specified, and there was no DefaultChallengeScheme found with default authentification and custom authorization .net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible Update .NET web service to use TLS 1.2 EF Core add-migration Build Failed What is the difference between .NET Core and .NET Standard Class Library project types? Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=4.1.0.0' or one of its dependencies Nuget connection attempt failed "Unable to load the service index for source" Token based authentication in Web API without any user interface

Examples related to sql-server

Passing multiple values for same variable in stored procedure SQL permissions for roles Count the Number of Tables in a SQL Server Database Visual Studio 2017 does not have Business Intelligence Integration Services/Projects ALTER TABLE DROP COLUMN failed because one or more objects access this column Create Local SQL Server database How to create temp table using Create statement in SQL Server? SQL Query Where Date = Today Minus 7 Days How do I pass a list as a parameter in a stored procedure? SQL Server date format yyyymmdd

Examples related to timespan

How to Convert string "07:35" (HH:MM) to TimeSpan Check if a given time lies between two times regardless of date Measuring code execution time Work with a time span in Javascript Getting time span between two times in C#? TimeSpan to DateTime conversion What is the correct SQL type to store a .Net Timespan with values > 24:00:00? Check if datetime instance falls in between other two datetime objects Showing Difference between two datetime values in hours C#: what is the easiest way to subtract time?