Sometimes we need to specify a time zone when using datetime functions in Oracle.
But there are a lot of time zones out there. How do we remember them all? And how do we know our system supports a given time zone?
Fortunately, we can query the V$TIMEZONE_NAMES view to return a list of valid time zones.
When working with functions that return dates, Oracle Database returns these dates based on the value of the NLS_DATE_FORMAT parameter.
There is also an NLS_TIMESTAMP_FORMAT parameter and an NLS_TIMESTAMP_TZ_FORMAT parameter, both of which have a datetime format mask that can be specified separately.
All of these parameters have their default values derived from the NLS_TERRITORY parameter (which by default, is operating system-dependent).
In Oracle Database, the NLS (National Language Support) parameters determine the locale-specific behaviour on both the client and the server.
These parameters can be set in various places, such as at the database level, in an initialization parameter file, in environment variables, at the session level, and even within some functions.
You can check the value of the NLS parameters with the following views.
Continue readingOracle Database includes a bunch of NLS (National Language Support) parameters that determine the locale-specific behaviour on both the client and the server.
These NLS parameters can be set in various places, each of which has a predetermined precedence order in relation to the others. The following table outlines these methods, as well as their priority in relation to the others.
Continue readingIn Oracle Database, the NLS_LANGUAGE initialization parameter specifies the default language of the database.
This language is used for messages, day and month names, symbols for AD, BC, a.m., and p.m., and the default sorting mechanism.
The NLS_LANGUAGE parameter also determines the default values of the NLS_DATE_LANGUAGE and NLS_SORT parameters.
This article outlines how to change the value of the NLS_LANGUAGE and NLS_DATE_LANGUAGE parameters.
When using Oracle Database, you can find out what languages are supported by querying the V$NLS_VALID_VALUES view.
This view lists all valid values for NLS parameters, including supported languages.
Continue readingWhen using Oracle Database, you can find out what territories are supported by querying the V$NLS_VALID_VALUES view.
This view lists all valid values for NLS parameters, including supported territories.
Continue readingWhen 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.
Continue readingIn 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).
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.
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