Here’s an example of using PostgreSQL to return the number of days in a month, based on a given date.
Continue readingTag: dates
Get the First Day of the Month in PostgreSQL
We can use the following method in PostgreSQL to return the first day of a given month.
This could be the first day of the current month, or the first day of the month based on a date that we specify.
Getting the first day of the month allows us to perform further calculations on the resulting date, like adding a certain number of days to the start of the month, etc.
Continue readingAdd Hours to a Time Value in PostgreSQL
In PostgreSQL, we can use the + operator to add one or more hours to a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also add hours to a date value or a date and time combination.
Calculate the Number of Seconds Since a Particular Date/Time in SQLite
If you need to calculate the number of seconds that have passed since a given date and time, you can use the UNIXEPOCH() function.
Note that this function was introduced in SQLite 3.38.0, so it will only work if you’re using SQLite 3.38.0 or later.
Continue readingAdd Days to a Date in SQLite
In SQLite, we can use the DATE() function to add a given number of days to a date.
If we’re dealing with datetime values, we can use the DATETIME() function.
2 Ways to Return the Julian Day in SQLite
Here are two methods for returning the Julian Day in SQLite.
The Julian Day is the fractional number of days since noon in Greenwich on November 24, 4714 B.C. It’s the continuous count of days since the beginning of the Julian period, and is used primarily by astronomers, and in software for easily calculating elapsed days between two events.
Continue readingSubtract Years from a Date in PostgreSQL
In PostgreSQL, we can use the - operator to subtract one or more years from a date.
Add Years to a Date in PostgreSQL
In PostgreSQL, we can use the + operator to add one or more years to a date.
Get the First Monday of a Year in SQLite
We can use SQLite’s DATE() function to return the date of the first instance of a given day of a given year. Therefore, we can use it to return the first Monday of a given year. We can also use it to return the first Tuesday, Wednesday, Thursday, Friday, etc.
We can use DATETIME() if we want a datetime value to be returned.
Add Weeks to a Date in PostgreSQL
In PostgreSQL, we can use the + operator to add one or more weeks to a date. We have a few options when it comes to specifying the actual number of weeks.