The time you spend on the various tasks of the day should ultimately contribute to the achievement of your goals. If you achieve this, you will have a productive day.
If you want to ensure that you have a productive day, you need to be able to allocate your time among the various tasks you have to complete throughout the day. That's what time management is all about, being able to use your time efficiently and productively.
If you're like everyone else, you probably look back on your day and wonder where all the time has gone, especially if you feel like you have nothing to show for it. If this happens often, the first thing you need to understand is why your time is not productive.