How to Format Timestamps and Dates in CSV Files

Last updated at:

Formatting Dates and Timestamps for CSV Files

If you're going to be uploading a CSV of data into Klaviyo, these are the datetime formats Klaviyo will recognize. Note that all formats must include both a date as well as time component. If there's no time of day associated with your date, you can set it to be midnight by using the HH:MM:SS value 00:00:00.


If you do not include seconds on your timestamps they will default to 0. For example, a timestamp of 2014-09-01 13:34 would be submitted to Klaviyo as 2014-09-01 13:34:00

For example, the date September 1st, 2014 at 1:34:08 p.m. should be formatted using one of the following supported formats:

2014-09-01 13:34:08

2014-09-01 13:34:08+00:00

09/01/2014 13:34:08

09/01/14 13:34:08

09/01/2014 13:34

09/01/14 13:34


1409529600 (Unix)

How to Upload These Properties into Klaviyo

Below is an example of how you would upload your master list with custom properties "Date Added - Old ESP," "Last Open - Old ESP," and "Last Click - Old ESP" with one of the correct datetime formats.


Was this article helpful?
27 out of 55 found this helpful