dropping a partition from an interval partitioned table

Hello everyone.

I am building a procedure to drop a single partition from an interval partitioned table based on a date (oracle version - 11.1.0.7). The goal - is to let other users to drop a partition from a table in another schema as part of a purge process. We have been doing similar things for a while, but this is the first time I use an interval partitioned table (most of other tables are partitioned by range). The partitions are weekly. So we will have partitions with high values , say April 7, April 14, April 21, April 28. May 5 etc.

Here is my concern. Lets say someone runs the procedure to drop partition containing  April 5th  via