# 1.8 Technical note: dates All dates are represented as a number of milliseconds, not as Javascript date objects. The time zone of a chart is user-configurable. The dates you receive, in data.dates or data.barData.date, are the user's chart time, not UTC. Similarly, any dates which you need to pass back to the chart, such as co-ordinates for creating a drawing or an event marker, also need to be numbers of milliseconds representing chart time rather than UTC. If you need to convert the chart times to UTC (or another time zone), then you can use the helper functions described below. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://sway-technologies.gitbook.io/sway-charts-pro-scripts-documentation/sway-charts-pro-user-defined-indicators/introduction/1.8-technical-note-dates.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.