Timezones and the SOAP API

We often get questions on DateTime fields in the SOAP api, and how Marketo handles them (yes, this applies only to SOAP).
So, rule #1. Always use W3c formatted dates. What's that, you ask? I'm glad you asked.. here are the details on Date and Time Formats
Timezone (U.S. Pacific): 2015-11-09T16:19:52-07:00
No Timezone: 2015-11-09T16:19:52
So the issue here is how DateTimes are handled when the timezone is not specified.
- For a custom object the timezone is assumed to be the same as the instance into which the request is sent. That's configurable in the admin section.
- For a lead, the time is assumed to be US Central Time (GMT-0600)
To avoid this, simply specify the DateTime.
