In this tutorial, we will explore different ways to convert a date to a Unix timestamp in Excel. We will also cover how to convert a timestamp back to a date. If you're a programmer looking for a quick solution, you've come to the right place. Let's dive in!

## Method 1: Using the TEXT Function

The first method involves using the TEXT function in Excel to convert a date to a Unix timestamp. The TEXT function allows you to format a value as text using a specified format code. In this case, we will use the format code "yyyy-mm-dd hh:mm:ss" to convert the date to a timestamp.

Here's how you can do it:

- Assuming your date is in cell A1, enter the following formula in cell B1:
`=TEXT(A1, "yyyy-mm-dd hh:mm:ss")`

. - Press Enter to get the Unix timestamp in cell B1.

Let's see an example. Suppose cell A1 contains the date "2023-07-29 12:34:56". By applying the formula above, cell B1 will display the Unix timestamp equivalent of that date.

```
A1: 2023-07-29 12:34:56
B1: 1677580496
```

You can also customize the format code to include or exclude specific parts of the timestamp, such as the time or seconds.

## Method 2: Using the DATEVALUE and TIMEVALUE Functions

The second method involves using the DATEVALUE and TIMEVALUE functions in Excel to convert a date and time separately to their respective values. Then, we can add these values together to get the Unix timestamp.

Here's how you can do it:

- Assuming your date is in cell A1 and time is in cell B1, enter the following formula in cell C1:
`=DATEVALUE(A1) + TIMEVALUE(B1)`

. - Press Enter to get the Unix timestamp in cell C1.

Let's see an example. Suppose cell A1 contains the date "2023-07-29" and cell B1 contains the time "12:34:56". By applying the formula above, cell C1 will display the Unix timestamp equivalent of that date and time.

```
A1: 2023-07-29
B1: 12:34:56
C1: 1677580496
```

This method allows you to handle dates and times separately, giving you more flexibility in your calculations.

## Method 3: Using the Excel Epoch

The third method involves using the Excel epoch, which is the starting point for Excel's date and time calculations. In Excel, the epoch is January 1, 1900, and it is represented by the value 1. We can calculate the number of days between the desired date and the epoch, and then convert it to seconds by multiplying it by 86400 (the number of seconds in a day).

Here's how you can do it:

- Assuming your date is in cell A1, enter the following formula in cell B1:
`=(A1 - DATE(1900, 1, 1)) * 86400`

. - Press Enter to get the Unix timestamp in cell B1.

Let's see an example. Suppose cell A1 contains the date "2023-07-29". By applying the formula above, cell B1 will display the Unix timestamp equivalent of that date.

```
A1: 2023-07-29
B1: 1677580800
```

This method is straightforward and doesn't require any additional functions. However, keep in mind that it assumes the date is after the Excel epoch.

## Converting Timestamp to Date in Excel

Now that we've covered how to convert a date to a Unix timestamp, let's explore how to convert a timestamp back to a date in Excel. We can use the reverse of the formulas mentioned above to achieve this.

Here's how you can do it:

- Assuming your timestamp is in cell A1, enter the following formula in cell B1:
`=DATE(1900, 1, 1) + (A1 / 86400)`

. - Press Enter to get the date in cell B1.

Let's see an example. Suppose cell A1 contains the Unix timestamp "1677580496". By applying the formula above, cell B1 will display the date equivalent of that timestamp.

```
A1: 1677580496
B1: 2023-07-29
```

This formula works by calculating the number of days between the Excel epoch and the timestamp, and then adding it to the Excel epoch date.

## Related Content

- Excel TEXT function documentation
- Excel DATEVALUE function documentation
- Excel TIMEVALUE function documentation

## Conclusion

In this tutorial, we explored different ways to convert a date to a Unix timestamp in Excel. We learned how to use the TEXT function, the DATEVALUE and TIMEVALUE functions, and the Excel epoch to achieve this. We also covered how to convert a timestamp back to a date using the reverse of these formulas. Now you have the tools to work with Unix timestamps in Excel. Happy coding!