Teradata 13.10 Statistics Collection Recommendations - comment by carrie

Based on what you say, when stats were collected on Sunday (day 07), there are no rows in the partition for day 06 and no rows in the partition for day 07 and no rows yet in the partition for day 08.   So the explain text row count estimate of 1 row for a query that selects only partitions for day 06, 07 and 08 seems accurate to me.   (You will always get a one row estimate even when no rows are detected in a table or a partition).
 
The recommendation is to re-collect statistics if either the table or any partition in the table changes by 10% or more. Going from an empty to a full partitions qualifies as more than a 10% change to a partition.  So you need to recollect on PARTITION and the partitioning column after any load activity into an empty partition. 
 
If you ever find yourself getting bad plans on your current schedule of recollections, but are able to get good plans with more frequent recollections, then it makes a lot of sense to recollect more frequently. 
 
Thanks, -Carrie