Database Management Systems
In MySQL, you can use the DATE_SUB() function to subtract a specified amount of time from a date. For example, you can use it to subtract 7 days from a given date. You can specify whether to subtract days, weeks, months, quarters, years, etc. You can also subtract a time value, such as seconds, microseconds, etc.
This function is similar to DATE_ADD(), except that it subtracts from a date instead of adds to it.
In MySQL, you can use the DATE_ADD() function to add a specified amount of time to a date. For example, you could use it to add 5 days to a given date. You can specify whether to add days, weeks, months, quarters, years, etc. You can also add a time value, such as seconds, microseconds, etc.
This article contains examples that demonstrate how the DATE_ADD() function works.
In MySQL, you can use the ADDDATE() function to add a specified amount of time to a date. For example, you could use it to add 10 days to a given date. You can specify whether to add days, weeks, months, quarters, years, etc. You can also add a time value, such as seconds, microseconds, etc.
The ADDDATE() function is a synonym for the DATE_ADD() function (they both do the same thing) when using the first syntax listed below.
This article contains examples to demonstrate usage of the ADDDATE() function.
This post contains a list of Transact-SQL date and time functions available in SQL Server (as of SQL Server 2017).
This includes functions that return the date or parts of the date, as well as functions that manipulate and/or format the date.
In SQL Server, the first day of the week is determined by the current language settings. You can also override that with the SET DATEFIRST statement, which allows you to explicitly set the first day of the week.
In either case, you can use the @@DATEFIRST function to find out what settings your session is using for the first day of the week. This article demonstrates how.
In SQL Server, you can use SET DATEFIRST to set the first day of the week.
The first day of the week can be different, depending on the language being used. For example the default for us_English is 7 (Sunday), whereas the default for Deutsch (German) is 1 (Monday).
This article demonstrates how to change the first day of the week without changing the language.
In SQL Server, you can use the YEAR() function to return the “year” part of a date. This is returned as an integer.
Below are examples of how to use this function.
In SQL Server, you can use the MONTH() function to return the “month” part of a date. This is returned as an integer (not the month name).
Below are examples of how to use this function.
In SQL Server, you can use the DAY() function to return the “day” part of a date. This function returns an integer that represents the day of the month (not the day of the week).
Below are examples of how to use this function.
In SQL Server, the T-SQL SYSUTCDATETIME() function is used to return the current UTC time (Coordinated Universal Time). UTC time is the primary time standard by which the world regulates clocks and time.
The return value of the SYSUTCDATETIME() function is derived from the computer on which the instance of SQL Server is running. The time zone is not included, and it is returned as a datetime2 value. The fractional second precision specification has a range from 1 to 7 digits. The default precision is 7 digits.
SYSUTCDATETIME() does the same thing that GETUTCDATE() does, except that it returns a higher fractional precision. As mentioned, SYSUTCDATETIME() returns a datetime2 value, whereas the GETUTCDATE() function returns a datetime value.