I just back today. vs I just back on today.

Some examples from the web:

• Something Cassie said yesterday struck me as weird. So, I just, I went back today.
• I've been out of town. I just got back today.
• I can come back, just not today.
• Just go back home for today.
• I promise we'll get Kol back, just not today.
• Out of nowhere, he paid Hector back today.
• They said I could get my laptop back today.
• She's expecting me back today.
• The bad news is he's back today.
• All right, farther back today.
• Lady Mary and Anna are coming back today.
• And I bet you anything he's bringing Holly back today.
• Yes, and the pregnancy test comes back today.
• I got my license back today.
• I'm glad you could come back today.
• But they got to fly back today.
• You know, Tommy's coming back today.
• I was burning some brush out back today.
• -Bob knows that you are coming back today.
• You gave me my life back today.

Some examples from the web:

• I've been out of town. I just got back today.
• Something Cassie said yesterday struck me as weird. So, I just, I went back today.
• I can come back, just not today.
• Just go back home for today.
• I promise we'll get Kol back, just not today.
• I just felt like something was going on today.
• Well, there was a mix-up with the bill and they shut my phone off, but it should be back on today.
• There's a lot going on today.
• The TV literally turned itself on today.
• I filled out the application when we first got back together, and I just got it today.
• I just want you to know I'm not coming back into the office today.
• - Actually, we're just back on break.
• I appreciate the sentiment, but nothing's going on today.
• There are hundreds of weddings going on today.
• There will be a further bulletin later on today.
• Got a lot going on today.
• Didn't think you were on today.
• The Large Mart has the same promotion going on today.
• Well, like Brian, for example... has thirty-seven pieces of flair on today.
• I have nothing to report on today.