I didn't have any issues with it smudging during the day but I didn't like the formula; I found it to be too thin and watery. I had to repeatedly wipe the brush clean of the runny excess liquid because there was just way too much. I also found that it applied a bit transparent in some areas so I had to go over it a few times.
The brush itself was okay, I liked that it had some flexibility and it was a good size to achieve a thin line or to build up a thicker line like I did.
I can use this liner over other liners if I want to darken them up but overall I don't care for it very much.