Setting up Chart Time Frame

In general, setting up a time frame for your chart involves two things: defining a time interval, which is a time range for which the entire chart is plotted, and specifying an aggregation period, i.e., a period during which price data is accumulated for one bar (or candle, line segment, etc.). The latter can be expressed in time units, ticks, or price range accumulation. The Charts interface provides you with a number of standard time frames, however, you are free to create your own. If you switch often between time frames, consider adding the most frequently used to your favorites so they are always at hand.

To set up a time frame:

1. Click on the Time Frame button above the chart, next to the gear button. The Time Frame Setup menu will appear. To access this menu, you can also click the Style button and then select Time Frame Setup or just press Ctrl+T on your keyboard.

2. Click on the Time frame tab and select the Aggregation type you prefer to use: Time, Tick, or Range.

3. If your choice is Time aggregation, specify which kind of time aggregation you wish to set: standard intraday (each bar is completed in 24 hours or less), standard daily (each bar takes at least 1 day to be completed), or custom (you can specify both intraday and daily periods there). 

Note on using 24-hour candles: A candle with an aggregation of 24 hours is an intraday candle that spans the entire day, Midnight to Midnight CT regardless of instrument-specific rollover time.
It means that while a forex daily candle contains quotes from 4PM CT till 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 enables you to use the Extended-Hours Trading feature as the candle's span includes trading data outside the market hours.
Note, however, that the GetAggregationPeriod function returns the same value when used on charts with either aggregation.

4.  Specify the desirable time interval. For intraday aggregations, it cannot be more than 360 days, for tick aggregations - not more than 5 days. Abbreviations: WTD stands for "week to date", YTD is "year to date", and Max available means that the chart will load all the available price data for the symbol (note: there are symbols that can be charted all the way back to 1902).

5. If you've selected the custom time aggregation, you can specify a certain time period in the past (if there is available price data for that period) or a number of years/months/days up to today. Specifying the latter will display all the available chart data for the period and when the current day is over, the chart will keep updating and the left-hand chart limit will be pushed forward one day. Please note the difference between the From-To and Up to today controls: should you select the current date in the To box in the former control, the chart will stop updating at midnight CST (Central Standard Time).

6. Specify the aggregation period. You can choose a pre-defined value from the list, type in a value in the combo box (for time aggregations, the format is hh:mm), or drag the slider so it displays the desirable amount of time/ticks/range units. On the list, Opt Exp means that the period between two consecutive expiration Fridays is taken to aggregate data for one bar.

7. If you wish to add your aggregation to Favorites, click on the star icon in the bottom left corner of the dialog window. It will be added to the list on the Favorites tab; to access this list further on, just click on the Time Frame button (see step 1). To customize the list of favorite time frames, click Customize list... below it so you will be redirected to the Favorite Time Frames dialog in the Chart Settings menu.  

8. When you click OK on the Time frame tab or select a time frame from the Favorites, the chart will be updated accordingly.