DuckDB provides us with a good selection of functions for working with dates and timestamps. One of the things we might find ourselves needing to do is extracting the ISO weekday from a date or timestamp—a numeric value where Monday is represented as 1 and Sunday as 7.
This article presents four functions we can use to get the ISO weekday from a date in DuckDB.
Continue readingIn DuckDB, the strptime() function converts a date/time string into a valid timestamp value. We pass a format string to the function in order to tell it what format our string uses. This can be handy if we ever need to construct timestamps based on date/time strings that may or may not be in a valid format.
But what if we have multiple date/time strings in different formats?
Fortunately, the strptime() function caters for this scenario too.
When working with dates in DuckDB, sometimes we need to extract date parts from date or timestamp values. And when it comes to date parts like days and months, we have the option of getting the numeric representation or the actual name. And if we want the name, we have a further option of getting the full name or the shortened version.
For example, we can get December or we can get Dec.
Continue readingSQLite is a lightweight, self-contained relational database management system that is widely used due to its simplicity and portability. However, one notable aspect of SQLite is its lack of a dedicated DATE or DATETIME storage class. Instead, SQLite stores date and time values as integers, real numbers, or text, depending on how the developer chooses to manage these values.
In this article, we’ll explore how to effectively use and store dates in SQLite, and provide examples that may help you implement date management in your projects.
Continue readingIn the ISO-8601 calendar, years begin on the first Monday closest to January 1, meaning the start date can fall between December 29 and January 4. This differs from the Gregorian calendar, where years always start on January 1, leading to potential discrepancies around these dates. Additionally, ISO-8601 years, or just ISO years, can be either 52 or 53 weeks long, depending on their starting point.
This article provides four options for extracting the ISO year from a date in DuckDB, accounting for these unique calendar rules.
Continue readingTime-based operations are a fundamental aspect of data analysis and manipulation. DuckDB, the in-process analytical database management system, provides robust support for handling time-based operations through its INTERVAL data type.
This article explores the capabilities, syntax, and practical applications of intervals in DuckDB.
Continue readingWhen working with DuckDB, sometimes we might need to get the weekday name from a date or timestamp value. And sometimes we might want just the abbreviated weekday name, rather than the full name. For example, we might want Mon instead of Monday.
Continue readingWorking with dates often requires extracting specific components, such as the week number, for analysis or reporting. In DuckDB, there are multiple functions to retrieve the week from a date, each catering to different needs. This article explores four such functions, including how to calculate the ISO week—a standard defined by ISO-8601 where weeks start on Monday and the first week of the year contains the year’s first Thursday.
Continue readingIn DuckDB, the strftime() function is a handy tool for formatting date and timestamp values as strings. It accepts the date/timestamp value and a format string as arguments. The function then returns the date/time in the format provided by the format string.
When working with SQL databases such as DuckDB, dates usually conform to a specific format. In particular, when we create dates in DuckDB, they must conform to the ISO 8601 format (YYYY-MM-DD). It’s the same with time (hh:mm:ss[.zzzzzz][+-TT[:tt]]) and timestamp values (YYYY-MM-DD hh:mm:ss[.zzzzzzzzz][+-TT[:tt]]).
But what if we have a requirement to present these dates or timestamps in a different format?
Fortunately, DuckDB provides us with tools to so. This article explains how to format date and timestamp values according to a specified format.
Continue reading