Setup [Today] as default to the sharepoint date time control through browser

Step1:

Create a new date time field and set the calculated value as “Today”. That’s it.

Create a new item into the list. There you can see set the Today’s date as default to the date time field.

Step2: 
Creata new item into the list and there you will see the set the Today's date as default to the sharepoint date time field.[PFB the image]