The Natural HR Report builder feature provides the ability to create reports based on a specific date or dates. In the 'Absolute' section the filter is set for a field which must meet criteria for a specific date or dates. In the Relative section, the date you want to report on will be a period of time relative to today's date and not tied to a specific date e.g. a date which occurs this week, this month, this year etc. 

So any record falling in to that time span will be reported. In this example there are three training records set up for the 5th, 6th and 7th of the same month.  A report has been created using the Training data source and a filter applied:

Training date - this is actually the start date of the training

This Week

Here we can see all three training records where their Training dates (start date) all occur in this week.

There are three relative date options which are more specific to a day rather than a date span or range, they are

• Today
• Next Day
• Previous Day

If we create the same report but choose 'Today' then the report will show only the training record where the Training date (start date) is today, 10th.

Assuming today's date is the 10th of the month, then selecting 'Previous day' (Yesterday) will report the Training date starting the 9th. For 'Next day' (Tomorrow) the report will return the training starting on 11th.