Why Sql Date 19000101

SQL Programming

In this article, I will delve into the fascinating world of SQL dates and explore why the date 1900-01-01 holds a special significance. As a database enthusiast, I find it fascinating how a seemingly arbitrary date can have such an impact on the world of SQL.

A Brief Introduction to SQL Dates

Before we dive into the significance of the date 1900-01-01, let’s take a moment to understand how dates are stored and manipulated in SQL. In SQL, a date is represented as a data type called “DATE.”

SQL dates are typically stored as a combination of year, month, and day values. This allows us to perform various operations on dates, such as comparing them, calculating differences, and formatting them according to our needs.

The Mystery Behind 1900-01-01

Now, let’s explore the mystery behind the date 1900-01-01. This date holds special significance in SQL because it is the default start date for the calendar in many database systems, including Microsoft SQL Server.

Back in the early days of SQL, when developers were designing the foundations of the language, they needed to establish a reference point for calculating and storing dates. Someone had to decide on a starting point, and that decision ultimately led to 1900-01-01 being chosen as the default start date.

By adopting 1900-01-01 as the starting point, database systems could represent dates as a simple numeric value, with each day incrementing the value by one. This made it easier to perform calculations and comparisons on dates, as well as manage date-related operations efficiently.

However, it’s important to note that not all database systems use 1900-01-01 as the default start date. Some systems, like Oracle, use different date formats or have a different starting point altogether. Therefore, it’s always essential to be aware of the specific conventions and standards followed by the database system you are working with.

Personal Reflections

As a database professional, I find it fascinating how a seemingly trivial decision, such as choosing a default start date, can have a lasting impact on an entire technology ecosystem. The choice of 1900-01-01 as the default start date has shaped the way we work with dates in SQL and has become deeply ingrained in the language’s syntax and functionality.

At times, it’s easy to take the default start date for granted and overlook the thought and consideration that went into its selection. It serves as a reminder that even the smallest decisions can have far-reaching consequences.


In conclusion, the date 1900-01-01 holds significant importance in the world of SQL as the default start date for many database systems. It serves as a reference point for calculating and manipulating dates, allowing for efficient date-related operations. Understanding the origins and implications of this default start date provides insights into the inner workings of SQL and the decisions that shape our technology landscape.