This may be a limitation of the backend database, which by default is HyperSQL Database (HSQLDB) version 1.8 - if you are using the default backend, the documentation is at http://www.hsqldb.org/doc/1.8/guide/ch09.html and does not have anything like ALTER VIEW or REPLACE VIEW. You have to use DROP VIEW, which is only allowed if there are no dependencies.
You have the option to upgrade to the current version of HSQLDB (version 2.3), which supports the ALTER VIEW statement (http://hsqldb.org/doc/guide/guide.html#dbc_view_creation). The GUI would probably still not support the transaction, but you could use the Tools->SQL window to directly issue the ALTER VIEW command to the database. Instructions on how to upgrade the database component to version 2.3 is in this forum thread: [Tutorial] Splitting an "embedded HSQL database"
Alternately, instead of hard-coding a particular date into the view's SQL, have the view reference a filter/dummy table for the date. Then you can just open up the one-column, one-row "reportDate" table and alter the date in there each week without touching the view.