un-graceful error notification when setting up a report with a non-existent date

[s4069b]

I was updating a report and entered a non-existent date (31st November)...

It was my mistake, but rather than politely warn me of my error Jethro returned multiple pink error boxes and I needed to guess what my mistake was.

I reconfigured the report with 30th November and Jethro was happy with me again