How to update contact datepicker field value via Contact API?




I’m trying to update contact’s custom field (datepicker type) value via API [0] , and API returns error message “Property values were not valid” . Tried sending different values (“2016-10-05”, “2016-10-05 11:11:11”, timestamp), no success. Do you have any recommendations or sources what to read to solve this issue? I could not find anything related to value requirements.



Hi @Antanas_Koncius

Datepicker properties need to be set using a UNIX formatted timestamp in milliseconds. More details can be found here:


thanks! Directionally it was good, just had to reverse-engineer value: for me for some reason “midnight” was 03:00:00 , not 00:00:00, probably because of timezones or something, but it was weird and unexpected and error message wasn’t helpful in debugging why my provided value is invalid for API :slight_smile:

anyway, solved issue, thank you!


@Antanas_Koncius the reason is that UNIX timestamp represents how many milliseconds have past from unix-time epoch in GMT+0

So you have to adjust for the time zone change depending on how far you are from GMT +0.


I can’t get update of datepicker field value to work the following way:


“properties”: [
“property”: “trial_user_create_date”,
“value”: “1411084800”


Hi @HenrikJanningJuul,

It looks like you’re passing a timestamp in seconds since midnight, not milliseconds since midnight. Most likely what you want to be passing is 1411084800000 not 1411084800.

You can refer to this document for more info:


Thanx a lot - you just saved my day :slight_smile:



I tried these timestamps:
1480032000000 (2016-11-25 00:00:00) - accepted
1480035600000 (2016-11-25 01:00:00) - bad request