See here: Format for importing CSV into project with Date/Time field?
When importing a list of tasks into a project via CSV, it’s not possible to import a date into a Date custom field, if that date also has a time.
Please let us import dates AND TIMES into a date format (especially since that’s supposed in both the UI and the API).
When doing a CSV import into a project that has a Date custom field, no matter what format we try within the CSV, Asana won’t let us choose the desired Date field during the import step.
My custom field is a Date format with both date and time, and I’ve tried the following based on various documentation I’ve found:
1/16/2025 2:36 PM2025-01-16T19:36:00:000Z
Looking at the API output, it uses format of:
2025-01-16T19:36:00:000Z
All the import dropdown selection says is “Values must be in date format”… but they are. Not very helpful. Especially when the “Help” article mentions:
Date fields: Enter the values using ISO timestamp.
Date only (no time) works fine.