Here are three methods we can use to return the first day of a given month in MySQL.
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 readingIn SQLite, we can use the TIME() function to add a given number of seconds to a time value.
If we’re dealing with datetime values, we can use the DATETIME() function.
In PostgreSQL, we can use the - operator to subtract one or more hours from a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also subtract hours from a date value or a date and time combination.
Below are examples of using some of the more popular RDBMSs to return the Unix timestamp.
The Unix timestamp (also known as Unix Epoch time, Unix time, or POSIX time) is the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC).
Continue readingHere are two options for returning the number of days in a given month in SQLite. This could be the number of days in the current month, or it could be based on a given date.
Continue readingIn PostgreSQL, we can use the to_timestamp() function to convert a Unix timestamp value to a date/time value.
The Unix timestamp (also known as Unix Epoch time, Unix time, or POSIX time) is the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC).
Continue readingWe can use the - operator to subtract one or more weeks from a date in PostgreSQL.
We can use SQLite’s DATE() function to return the first Monday of each month for a given year, based on the date we provide.
But it’s not limited to Monday. We can also get the first Tuesday, Wednesday, Thursday, Friday, etc of each month.
Continue readingWe can use the following technique in PostgreSQL to return the last day of a given month.
This could be the last day of the current month, or the last day of the month based on a date that we specify.
Continue readingCheck out the following technique in MySQL if you need to find out how many days are in a month based on a given date.
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