With Oracle Database, we can use the TO_CHAR(datetime) function to return a datetime value, formatted in a way that we specify.
We can use this function to return the day name from a date (as well as any other parts of the datetime value).
dates
How to Calculate Age in MariaDB
In MariaDB, you can use the TIMESTAMPDIFF() function to calculate a person’s age (or the age of anything for that matter).
TIMESTAMPDIFF() is a built-in date and time function that returns the difference between two date or datetime expressions. Passing YEAR as the first argument, date of birth as the second argument, and the current date as the third, will return the age in years.
2 Ways to Get the Day from a Date in Oracle
Below are two functions that can be used to return the day from a date in Oracle Database.
2 Functions to Get the Year from a Date in Oracle
Below are two functions that can be used to extract the year from a date in Oracle Database.
How to Check the Date Format of your Oracle Session
When working with functions that return dates, Oracle Database returns these dates based on the value of the NLS_DATE_FORMAT parameter.
There is also an NLS_TIMESTAMP_FORMAT parameter and an NLS_TIMESTAMP_TZ_FORMAT parameter, both of which have a datetime format mask that can be specified separately.
All of these parameters have their default values derived from the NLS_TERRITORY parameter (which by default, is operating system-dependent).
How to Change the Date Format in your Oracle Session
When working with functions that return dates, Oracle Database returns these dates based on the value of the NLS_DATE_FORMAT parameter.
There is also an NLS_TIMESTAMP_FORMAT parameter and an NLS_TIMESTAMP_TZ_FORMAT parameter, both of which have a datetime format mask that can be specified separately.
All of these parameters have their default values derived from the NLS_TERRITORY parameter (which by default, is operating system-dependent).
So, to change the date format for your session, you can either update the NLS_TERRITORY parameter, or explicitly update each parameter individually.
This article provides examples of checking and changing these values, and viewing the results.
How to Get the Short Day Name from a Date in MariaDB
In MariaDB, you can use the DATE_FORMAT() function to return various date parts from a date. One of the things you can return is the short day name. For example Tue or Wed (instead of Tuesday or Wednesday).
3 Ways to Convert a String to a Date in MongoDB
If you have a MongoDB collection with dates stored as strings, you can convert those into the Date BSON type if required.
Below are three ways to convert a string into a Date in MongoDB.
Change the Time Zone Offset on a datetimeoffset Value in SQL Server (T-SQL)
You can use the SWITCHOFFSET() function in SQL Server to change the time zone offset on a datetimeoffset value.
The function accepts two arguments; a datetimeoffset(n) value (or an expression that can be resolved to a datetimeoffset(n) value), and the new time zone.
MongoDB Aggregation Operators for Returning Date Parts
This article lists the various aggregation pipeline operators that can be used to return individual date parts from a Date object in MongoDB.