They are gobbling right now. I listened to several toms last week in the mountains where I'll call for a buddy with a limited special license and I heard toms gobbling this morning in a cottonwood riverbottom in Eastern MT. This morning was a little windy and rainy, so they didn't want to talk much.
You can be sure of one thing.......there is no absolute with turkeys.
They typically like to gobble the most in the mornings. They'll start gobbling from the tree well before they fly down on days that they are gobbling good. They'll gobble throughout the morning (the day sometimes). They'll gobble more if they don't have hens with them because they are lonely. If they have hens, they'll hit the ground gobble a few times then spend most of their time strutting with the occasional gobble. It may be a gobble at a hen yelping or a shock gobble at a crow that flies over and makes a lot of racket.
They will also gobble in the evenings. Primarily just before and after they fly up into the tree. Merriam's for the most part are blabber mouths and will readily gobble on the roost in the evenings more readily than a typical Eastern will.
When you are hunting, try to get within a reasonable distance to roosted birds before they fly down. Base this on terrain and cover. "Close" may be as far as 300 yards if it's getting light and it's flat open country, but I like to make it to 150 or closer if conditions allow (I really like less than 100, but that can be pushing it). If you don't have them roosted, you can allow them to gobble on their own then take off in their direction. I like to try and get a response with an owl or coyote early enogh that I can get to distant birds before or soon after they fly down. Merriam's typically have a destination in mind and will sometimes start moving quickly, so I want to try and persuade them my directions ASAP.
If I can't find birds early or the birds I do find leave and shut up, I'll start covering ground on the ridgetops. At that point, I prefer to locate with loud excited yelping, but again.......allow the conditions to dictate that. I'll try to use a crow call also so I have plenty of time to set up if I hear a response, but if that isn't getting it done, I'll go right to loud yelping.
Just because you don't hear birds doesn't necessarily mean they aren't there, but instead it could just be one of those days that they keep their mouth shut. I'm not much on hanging out and waiting on silent birds, I go looking for one that wants to play. You run the risk of bumping birds that way, but it's still my preference. You just have to pay attention on public ground that you aren't running over someone else. I never call to a bird that someone else is already set up on and working, public ground or not. Everyone won't offer that same courtesy.
That may be more than you were looking for.