When it comes to forecasting, getting the dates correct is critical. When dealing with dates as strings the date formatting has to be correct. We use libraries in all languages that support ISO 8601 formats for interchanging dates.
If a Date/Time formatted string submitted does not contain a Time Zone indicator, Nexosis API will assume it to be UTC. If you request your DataSet back, it will be returned without the Time Zone indicator since we make an effort to not modify original submitted data.
All DateTimes, when represented as strings should be converted to the ISO 8601 format and include the TimeZone / Offset.
Here are some examples of libraries in different languages that can help you with this.