Looking on the internet deeply has found these results:

I am leaving for the day is the most popular phrase on the web.

I am leaving for today 141,800 results on the web	I am leaving for the day 12,980,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
David, I am not leaving today. or I am leaving... today! I am leaving today for Utah... ...where the transcontinental railroads will be joined at Promontory Point. But... They're leaving for Paris today. I'm leaving for Philadelphia today. By the way, I am leaving Strasbourg today and flying to Delhi to have discussions with the Indian Government and Indian representatives. Either you get rid of every hideous bird, beast and reptile... in this ridiculous menagerie immediately,	I'm getting my stuff. I'm leaving for the day. You were leaving for one day. I'm leaving for the day. Because I would actually like to bring them home and pack them, and I am leaving for the day at 4:00. I heard you were leaving for the day. But I am leaving for New York in a couple days. Meredith, I'm leaving for the day. Look, Mutant, I'm just grabbing a few of Mr. Magorium's things, and then I'm leaving for the day.

I am leaving for today

141,800 results on the web

I am leaving for the day

12,980,000 results on the web

More popular!

David, I am not leaving today.
or I am leaving... today!
I am leaving today for Utah... ...where the transcontinental railroads will be joined at Promontory Point.
But...
They're leaving for Paris today.
I'm leaving for Philadelphia today.
By the way, I am leaving Strasbourg today and flying to Delhi to have discussions with the Indian Government and Indian representatives.
Either you get rid of every hideous bird, beast and reptile... in this ridiculous menagerie immediately,

I'm getting my stuff. I'm leaving for the day.
You were leaving for one day.
I'm leaving for the day.
Because I would actually like to bring them home and pack them, and I am leaving for the day at 4:00.
I heard you were leaving for the day.
But I am leaving for New York in a couple days.
Meredith, I'm leaving for the day.
Look, Mutant, I'm just grabbing a few of Mr. Magorium's things, and then I'm leaving for the day.