Hi Mark,
Sorry for the late response, I haven't been on in the SCN in about a week. What I've experienced when entering entitlement amounts directly in 2013 without first creating the bucket in 2006 is that the validity interval is created incorrectly while the deduction interval is correct.In order to avoid the issue I recommend creating a record in 2006 with 0 hours and the correct validity and deduction intervals and then filling those "buckets" with hours using infotype 2013. Once you have created the 2006 and 2013 records you will need to run time evaluation. The quota itself won't accrue until time evaluation is run ON the date of the 2013 records. So if you create the 2013 record to generate 40 hours of entitlement on 01/07/2015 then no entitlement will be generated until that date is processed in time eval.
Thanks,
Kory