• APD:2005  -->  Finds documents filed in 2005.
• APD:03/06/2001 --> Finds documents filed on the specific date of 03/06/2001.
• APD:[2000 to 2014] -->  Finds documents filed any time from 2000 to 2014, inclusive of the end points.
• APD:[1970 to NOW] -->  Finds documents filed anytime from 1970 to today's date (also known as whatever day you run the search).
• APD:[NOW-10YEARS to NOW] -->  Finds documents filed within the last 10 years of today's date.
• APD:[NOW-18MONTHS to NOW]  -->  Finds documents filed within the last 18 months of today's date.
• APD:[NOW-1000DAYS to NOW-1YEAR]  -->  Silly query showing how you can mix days and years in the same query.

About Range Queries:

All date fields support Range Queries.  Range Queries let you search for patents that fall within specific date ranges.  

Use square brackets so that the end points are inclusive.  Range Queries support curly brackets which exclude the endpoints, but they are generally not recommended since it is better to create inclusive queries.  This is because they read more naturally to most users.  For instance, the following two queries are the same:

APD:[2010 to 2012]

APD:{2009 to 2013}

Both of the above examples find documents filed in 2010, 2011, and 2012.  However, the first example is more natural.

Assume it's May of 2017 and I decide to run the following simple query:

APD:[2000 to NOW]

Now assume I decide to chart my results by both publication date and by filing date, and compare them.  Notice that there are many more published documents than filed documents by May of 2017.  It takes a while to get an application published.  So it is probable that none of those published in 2017 are actually from the filed pool from 2017!