Time Charts

Time charts are one of the most used chart types. They display data by grouping it into bars (or candlestick, line section, etc.) based on fixed time intervals. Each bar represents the price activity for the selected price type (such as Last, Bid, Ask, or Mark) during a fixed period of time, called the aggregation period. 

•  A 1-minute chart creates a new bar for each minute containing trading data.  
• A 1-hour chart creates a new bar for each hour containing trading data.
• A 1-day chart creates a new bar for each day containing trading data. 

If volume is displayed, the volume subgraph shows the total trading volume that occurred during each aggregation period.

Understanding Chart Time Frames

A chart’s timeframe is defined by two independent settings:

• Time interval: The total span of historical data displayed on the chart. 
• Aggregation period: The amount of time represented by each individual bar. 

The icon on the Time frame and Time frame setup buttons changes based on the selected settings, reflecting the current chart configuration.

• Į : Displays one year of data, aggregated into daily bars. 
• Ģ: Displays one day of data, aggregated into 1-minute bars.

To learn how you can set up a time frame, refer to this article.

Time Aggregation Options

When using Time Charts, you can select one of the following aggregation modes:

• Intraday: Each bar represents less than 24 hours. Commonly used for short-term and intraday analysis. 
• Daily: Each bar represents one full day or longer. Commonly used for swing trading and longer-term analysis. 
• Custom: Allows you to define a specific date range. Supports both intraday and daily aggregation periods. Useful for analyzing a fixed historical window.

How Time-Based Bars Are Built

Charts display data points (such as High, Low, Open, Close, and Volume) over defined intervals. For time charts, this interval is a fixed amount of time determined by the aggregation period. Each bar represents all applicable trading activity that occurred during that specific time period. To build these bars, the platform must determine when each specific time period starts. The fixed time interval bars are consecutive intervals based on that start time. The last bar may be truncated at the start of the next day. 

The start time used to build time-based bars depends on the type of price data and the data source supplying it. By default:

• Last price data is aggregated starting at Midnight Central Time (CT).
• Intraday bid, ask, and mark prices are aggregated starting at Midnight Coordinated Universal Time (UTC). 

Start aggregations at market open (Equities/Options/Futures)

By default, start times are determined by the data source. However, using the Start aggregations at market open setting you can offset the start time to align with the instrument’s regular trading session. To do this:   

1. Click the Chart settings " in the upper-right corner of the chart.
2. Open the instrument-specific tab (Equities, Options, Futures).
3. In the Time section, adjust the Show Extended-Hours Trading session and Start aggregations at market open settings as needed. 

This option is only available when Show Extended-Hours Trading session is turned off. When extended hours are displayed, the platform uses its default start time to maintain consistent aggregation across the full session, including pre and post-market overnight trading.

Setting Up Chart Time Frame

Setting a chart time frame involves defining two things:

• Time interval: The time range for which the entire chart is plotted.
• Aggregation period: The period for which price data is accumulated for one bar, candle, line segment, etc. This aggregation period can be expressed in time units, ticks, or price range accumulation.

The Charts interface provides you with several standard time frames and you can also create your own. To set up a time frame:

1. Access the configuration window using one of the following options:
   • Click the Time Frame button (by default, Į).
   • Click the ú Style button and select Time Frame Setup. 
   • Press Ctrl + T on your keyboard.
     Note that the icons on the Time Frame and Time Frame Setup buttons change based on the selected time frame. This enables you to identify chart configurations more easily.
2. Click the Time frame tab and select Time as the aggregation type.
3. Specify the type of time aggregation from the following options: 
   • Intraday: Each bar is completed in 24 hours or less.
   • Daily: Each bar takes at least 1 day to be completed.
   • Custom: Specify both intraday and daily periods.
     Note on using 24-hour candles: A candle with an aggregation of 24 hours is an intraday candle that spans the entire day (from Midnight to Midnight CT) regardless of instrument-specific rollover time. While a forex daily candle contains quotes from 4PM CT to 4PM CT of the next trading day, a 24-hour candle opens at Midnight CT and closes at Midnight CT of the next trading day. For equities, unlike the standard daily 1-Day aggregation, the 24-hour aggregation allows you to use the Extended-Hours Trading feature as the candle's span includes trading data outside market hours.
4. Specify the Time interval using the dropdown menu. The time interval defines how much historical data is displayed on the chart. Available options depend on the selected time aggregation type:
   • For intraday: Select a time interval from the current day up to 360 days. Options include predefined ranges such as WTD (week to date).
   • For daily: Select longer-term intervals, including YTD (year to date) and Max available, which loads all available historical data.
   • For custom: Define a specific time interval by either selecting a From-To date range or using Up to today to load data for specified number of days, months, or years up to the current date. Note that when using From-To with the current day as the end date, the chart stops updating at midnight CST (Central Standard Time). With Up to today, the chart continues updating after the current day ends, and the displayed range automatically shifts forward. 
5. Specify an Aggregation period using the dropdown menu or the slider. The aggregation period defines how price data is grouped into a single bar, candle, or line segment on the chart. The available aggregation period options depend on the time interval and aggregation type previously selected:  
   • For intraday: Select a value from the dropdown. The Opt Exp option uses the period between two consecutive expiration Fridays to aggregate data for one bar.
   • For daily: Select a value from the dropdown. Options like Opt Exp and Quarter are also available.
   • For custom: You can choose a value from the dropdown or use the slider.
6. Optionally, click the ù icon in the bottom-left corner of the window to add your Time frame configuration to your Favorites list. To access this list, click the Time frame button and select the Favorites tab. You can customize your favorite time frames by clicking Customize list.
7. Click OK to apply the selected time frame settings to the chart.