I can’t seem to access the month of April at the APOD site -http://129.164.179.22/apod/calendar/ca1204.html gives an error message. I can access March just fine - http://129.164.179.22/apod/calendar/ca1203.html
Try the non-working link next month. Here’s next month’s link:
http://129.164.179.22/apod/calendar/ca1205.html
April won’t work until April is done. It’s the same thing with the daily entries, even though they give you the title and link to it in the current day’s APoD.