Although the default time settings vary from one report type to another, the Time Selection screen allows you to tailor this dimension to meet your research objectives. Table 1 in the online help for the Data Source Selection page highlights the default time options for each report type. Through the Time Selection screen you can choose to include monthly data since 2002 and/or annual data since 1992, as well as add year-to-date (YTD) aggregations and growth rates to your report. Note: State-level data only goes back to 2002 and port-level data only goes back to 2003.

Navigating the Time Selections
Figures A and B below highlight how to access the main Time Selection screen. Choose "Time" from the Selection menu on your main report page and the Time Selection Screen will appear. Here, you must decide if you want to edit the current Time Series Sets or if you want to select individual time periods from the expanding list below.
You can create new sets ( ), edit the existing ones (), or even delete them using the icons featured in Figure B. This determines which time periods show up in your report. To edit or delete an existing time set, highlight it and press the Edit or Delete button.

Note: Deleting or Editing the time selections impacts your current report only. (It also effects the saved report if you save it.) When you return to the Data Source Selection, you'll get the system-defined default time periods again.

Time period sets vs simple time periods:

Users may be confused by the notion of "sets". In USA Trade Online, uniform, specific time periods (such as monthly data for 2006) can be represented fairly simply. But if you want to show something like year-to-date data or year-to-year changes, you have to use sets. If you want to mix monthly/annual data with year-to-date data, you need multiple time period sets. Sets are also used when you want to create a report that can be used in later months and have it automatically pick up the current time periods, not just the ones in existence when you created your report. All of the Data Source Selection reports incorporate time period sets.

To see the simplest approach to time periods, click the first red "X" in the "All" section -- . This will remove all pre-programmed time period sets. Now open any years you want to open by clicking the "+" next to any years you want monthly data for. Now select the individual months/years you want to see. Click "View table" and see what you got.

While this approach works, it's not recommended for any report that you want to save because the time periods will not be updated as more data are added to the database. For this, you need time period sets which are explained below.

Figure A: Selecting Time from the Selection Dimensions List

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Figure B: Top of the Time Selection Screen

Figure C: Bottom of the Time Selection Screen

Managing the Time Series

Creating New Time Series

Use this dialogue to create a new time series set. To begin, click the icon. This will bring up the screen shown in Figure D below. It shows all the existing settings for the current set. See the section More on these Individual Options below to help you determine which ones to select per report. Make your changes and click OK.

Editing the Time Series

Use this dialog to modify a previously-created time series set. To begin to edit an existing time series, click the icon. This will bring up the screen shown in Figure D. From here, select the Edit button. This will produce the screen shown in Figure E below.

To change the order of time series sets:

• Select a set and click Move up or Move down.

• Select a set and click the Edit button. The Edit time series set dialog appears as shown in Figure D. It shows all the existing settings for the current set. See the section More on these Individual Options below to help you determine which ones to select per report. Make your changes and click OK

• Select the set and click Delete as shown in Figure E. The set is deleted immediately.

Figure D: Time Series Sets Option Screen Figure E: Edit Time Series Sets Screen

• Name. This is where the name of whatever set you are using will appear (Monthly, Monthly - 1, Monthly - 2, Annual, Annual - 4, Current YTD, Cumulative YTD, or Cumulative YTD - 2). If you choose to Add your own set, the system will automatically name it "Advanced 1," however you can change it to anything you want!
• Periodicity. Here you choose either annual or monthly data. You cannot have both in the same time set. If you wish to have both annual and monthly data in your report, you must create two separate time sets.
• Show in reverse order. Here you can choose to show your data in reverse chronological order. The most recent periods show up first and the oldest last.
• Year-to-date Aggregations. Select this option if you want to include a YTD sum as one of your time settings.
• Base Period. This is the most recent year or month (again depending on what you selected for periodicity) that you wish to have in your report.
• Previous Periods. This is the number of previous periods (again this could be months or years) that you want in your report. This section allows you to conduct historical time series analysis. Since the current period is usually shown (unless "Exclude Base Period" is selected), your report will typically show the number of previous periods plus one. For example, if it is 2005 and I want to see historical annual data since 2002, I would select October 2005 as my base period and type in "3" for my "Previous Periods" category.
• Lag. This represents the spacing between periods. If the lag is 1, then the periods are consecutive. If lag is 2, then it goes over every other period. For example, if the base period is January 2005, there are 3 previous periods selected, and there is a lag of 2, then the months on the report would be January 2005, November 2004, September 2004, and July 2004. (Similarly, one previous period with a lag of 12 would show you January 2005 and January 2004.)
• Exclude Base Period. Check this box if you wish to remove the Base Period (the current month or year) from the report.
• Display. You can display values, growth rates, or values and growth rates. If you choose Values, only the unit(s) of measure that you selected on the Measures Selection screen will be included. The Growth Rate option calculates the rate of growth by dividing the change in value by the original value. Again, growth rates will be calculated and displayed for the units of measure that you selected on your Measures Selection screen. And finally, choosing Values and Growth Rate allows you to include both options in your report.
• Growth Type. If you have growth rates selected in the Display field, you will be able to use this field to choose exactly which type of growth rate you want to calculate. Standard: Growth rate between values specified is calculated. Average Annual: This is the same as the Standard growth type except adjustments are made for monthly growth rates. If Average Annual is selected, the monthly growth rate is divided by the number of days in that particular month and then multiplied by 365. This selection will only affect monthly growth rates. It will not affect annual or YTD growth rates.
• Between. This field will select which values the report will use to calculate the growth rates. All Periods: Growth rates are calculated from values for each time period and the time period following it. Rates are only calculated for time periods included in the report. (If you're showing 2002, 2003, and 2004 in your report, doing an "All Periods" growth rate shows two percentage changes -- one between 2002 and 2003, and then between 2003 and 2004.) First and Last Period: Growth rates are calculated from values for the first time period and the last time period included in the report. In any case, these are simple percentage change calculations. If trade is 2 in one period and 3 in the next, the growth rate is 50 percent (three minus two, divided by two, times one hundred).
• OK. Hit this button when you have finished making your customizations to the Time Selection screen otherwise your edits will not take effect and will return to the default.

• The current month is the default time period if the existing ones are cleared and nothing else is selected. The report page will load without a time header, but all the data listed will be for the current month of imports or exports depending on the type of report you chose in the Data Source Selection screen.
• USA Trade Online automatically saves any changes you make to your commodity, country, state, district or port (as applicable), and measures criteria before you view the resulting table. Only the "Advanced Selection" option in the time dimension requires you to save your changes first.
• Still can't find what you're looking for? Go to Frequently Asked Questions !