This appears to be the third time you've asked this question, despite already having had an answer. The answer you were given was accurate, so I can only assume you require confirmation that the rumour you've probably heard that rhubarb becomes poisonous as the season progresses is, in fact, rubbish. It is twaddle, along with little blue aliens and most conspiracy theories, its perfectly safe to eat, just don't eat the leaves. The level of oxalic acid in the stalks does increase over time, but not to a level that's going to poison you, unlike the leaves.

Yes of course its safe. I've made gallons of rhubarb jam later than this over the years and I'm still here.