23 or 24 April depending on which timezone you are looking at. If you have been stuck without update on your screen, I really recommend giving them a phone call and being nice. What they see on their screen is different to what we see on ours. They straightforward told me "ya on Eligibility you have been recommended you as "Passed" and are waiting for the security check" I was so happy I cried on the phone, so he was also quite happy to have helped giving me further info.
He also confirmed what people have known for a long time. Some will only update once a PPR or trouble comes, some will update periodically. So just answer nicely if asked like "you know it's still within the time frame, right?" DO NOT CHALLENGE DIRECTLY by going "it's my right, bla bla". Instead be nice and say "Yes, but I am aware that some may get updated less and less, we just want to prepare for anything". You need them more than they need you. Basically you want to prepare some bullet points that ask them to tell you what's on their screen and not to imply they need to reveal everything. Also, probably don't bother with terms like IP1, IP2, or anything. Just make it conversational.
Edit: I think I recalled you from the IELTS thread so it may not apply to you, but sometimes our language barrier makes us sound like we are bossing them around. Also asking technical questions may make them feel uncomfortable. Make it flow.
Really wish you to experience it VERY soon 
