Calculate age with timestamps

Hey there! Let's dive into how you can easily calculate someone's age based on their birthday stored as a timestamp in Xano. In this step-by-step guide, we'll explore the process and provide you with a handy code snippet to get you started.

Understanding Unix Timestamps

In Xano, birthdates are stored as Unix timestamps, which represent the number of milliseconds that have elapsed since the Unix epoch (January 1st, 1970, at 00:00:00 UTC). This means that timestamps before the Unix epoch will have negative values.

Calculating Age

To calculate someone's age from their birthday timestamp, follow these steps:

1. Get the current timestamp: First, you need to get the current timestamp in milliseconds. In Xano, you can use the now() function to achieve this.

2. Subtract the birthday timestamp: Subtract the birthday timestamp from the current timestamp. This will give you the number of milliseconds between the two dates.

3. Convert to years: To convert the difference in milliseconds to years, divide it by the number of milliseconds in a year. You can use the following constant for this purpose: 31557600000 (the number of milliseconds in a non-leap year).

4. Round down to the nearest whole number: Since we usually express age in whole numbers, use the floor() function to round down the result to the nearest integer.

Here's the formula to calculate age:

age = floor((now() - birthday) / 31557600000)

Example

Let's look at a practical example. Suppose you have a birthday stored as a string in the format "YYYY-MM-DD". You can use the following code to calculate the age:

data.age = floor((now() - parseDate("1950-01-01", "yyyy-MM-dd")) / 31557600000)

In this example, we're using the parseDate function to convert the string "1950-01-01" into a Unix timestamp. Then, we subtract this timestamp from the current timestamp (now()), divide by the number of milliseconds in a year, and use floor() to round down to the nearest whole number.

When you run this code, it will output the age corresponding to the provided birthday.

Code Snippet

To make it even easier, here's a code snippet you can add directly to your Xano workspace:

data.age = floor((now() - parseDate("{{birthday}}", "yyyy-MM-dd")) / 31557600000)

Replace {{birthday}} with the field in your data model that contains the birthday as a string in the format "YYYY-MM-DD".

This calculation works seamlessly for birthdays before or after the Unix epoch, as Xano handles negative timestamps without any issues.

Give it a try and let us know if you have any further questions! Happy coding with Xano!