# CA Clarity Tuesday Tip: Timeslices  - what are they?

Discussion created by wunru01 on Jun 12, 2012
Latest reply on Aug 18, 2012 by rahul.agrawal03
This is a very fundamental aspect of Clarity but there are often questions about time slices, what they are, what the different aspects of their definition mean etc.hence this posting as a reminder/clarifier.

Special thanks goes to Steve Robinson for his work on this.

Timeslices - what are they?

Time Slices hold time-varying data. This means any data that varies over time, such as Actuals, Allocations, Availability, Baseline, Estimates, and Time Entries.
Imagine a time slice as a ruler, where the ruler markings are the ‘Slice Period’, the length of the ruler represents the ‘Number of Periods’, the start of the ruler represents
the ‘From’ date (where the data starts) and the end of the ruler represents the end of the data window that the ruler represents.
So let’s imagine that a 12-inch ruler represents 12 months of data that starts on January 1, so you can see data to the end of December 31.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Now factor in the ‘Rollover Interval’ and the ‘Expiration’ date. The ‘Rollover Interval’ represents the amount of time the ruler will move to the right when the ‘Expiration’
date is reached. This is the rollover date.

For default timeslices, the interval is set by the system. For custom timeslice you can select the rollover interval.
If your rollover interval is monthly, the Expiration date will change on the first of each month.

So, at the start our ruler’s ‘Rollover Interval’ might be Monthly, and the ‘Expiration’ date might be July 1, which means when that date arrives, our ruler will shift to the right by one month. The result means that now our ruler starts on February 1 and finishes on January 31, so we still see 12 months of data but from the new ‘From’ date. Which means now our "ruler" shows:

Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

What this means is that our time-varying data regularly moves forward as time passes so that we constantly have up-to-date information in our Clarity views.
Data outside that timeslice definition will not be included/displayed in the portlets that are based on this timeslice.

All you need to do is decide where you want to place these ‘rulers’ and how long you want them to be.