Zoro received Enma 5 days before the festival.
By the way, Zoro has tremendously improve in less than 1 day to control Enma.
Oda starts by showing how Zoro is struggling with Enma
Zoro tried to cut a tree with Enma and he cound't. Instead he cut the whole cliff. Enma was draining to much Ryu without the willing of Zoro but right after he was able to call back his Ryu. There are three points to be aware:
If you want to use Enma, you need an insane amount of Hacky; Hitetsu said that any normal swordsman would become dust by just wielding Enma.
Zoro need to have a lot will-power and be able to focus to call back his Ryu. I am not sure why Oda decided to focus on Zoro's eyes for that process (maybe something relate CoC but that is an other topic).
And the last point is that Oden was the only one in Wano to use Enma. In 20 years no-one was able to use this sword. That mean that all current samurai even the powerful one can't use this sword.
In that panel, Kamawastu was extremely impressed by Zoro. Dont forget that Kamawastu is the strongest wrestler in Wano (one of the nine scabban), the one that protected Hyori in her childhood. He survived for 15 years in a prison with almost no food just by his will-power.)
So to conclude Zoro was able to call back his Ryu but he failed to follow the rule of the swordsman which is to cut only whatever he wants to cut.
Now, I am not sure how many hours later this scene take place but I think that it less than one day.
As you can see, Zoro is using Enma and if you see the bamboo plants they are cut in way that they are not falling down. Zoro is clearly using Enma and that mean he is able to control the amount of Ryu and to follow the rule of swordsman which is to cut only whatever he wants to cut.
This point for me is so important because this is the moment in which Zoro proves the same mastery that Oden had with Enma. They are both able to tame Enma.
Now we know that Zoro was training for more days, my question is how strong did Zoro become?