7 tips to get you the vacation time you deserve

Grenny warned that many employees take less time off because they assume it's the norm, and as a result, they let their vacation days go to waste.

"You need to figure out what you're comfortable with, and conversations are the vehicle for establishing expectations with others," said Grenny. "If you don't let [your boss and coworkers] express it to you explicitly, sometimes you hold yourself to a standard that they don't expect, and you end up taking less advantage of some of these generous policies than you could."

If you're a new hire, asking general questions about vacation time can help you out later on when it's time to ask for time off yourself.

Grenny gave sample questions to ask your boss: "How does it typically work? What do people typically do? Can you give examples of people who have abused it? So now I know what both normal looks like and what abuse looks like, and I can find my way in between those two guardrails."

Watching for norms is one of the easiest ways to figure out the right time and place for asking for PTO.

"See if you can get a sense for what the norms are for the people around you," said Grenny. "What kind of rhythms do they use? What lengths of vacation? How much time away?"

According to Grenny, it's important to make a mental note of how present other employees are while they're on vacation. "What boundaries does the workplace tend to honor in terms of when you're out? Are you really out, or do they intrude on your time for conference calls and for brief tasks?"

If you're new to the workforce, or if you're a new hire, make sure you're asking for PTO once you've earned it.

Grenny emphasized the importance of earning your place in the company before going on vacation. "I think it is important to be sensitive to earning social capital before you draw down on it," he said. "So if you're brand new and you're asking for a month off to go and traipse around Europe, you ought to expect what people are going to wonder about your level of commitment to the workplace. Realize that the first thing you need to demonstrate is that you care about the problems, issues, and concerns of the workplace. And once you've demonstrated that, then you have something to draw down on."

As Americans take more and more days off each year, Grenny argues that there's no need to leave your vacation days untouched.

"I think the norm these days is that people want you recharged," he said. "People recognize that we're complex human beings. For many of us [work] is a 24/7 thing because electronics intrude so much in our lives, so when we're away, we need to be away."

Grenny described his past experience with the dangers of observing norms without talking directly to the boss, where employees took less and less time off, thinking they were benefitting the company. Grenny called this a "race to the bottom."

"I've worked with many senior leaders in organizations that realize that they have a toxic culture that grinds people down, and that they need to have boundaries of going out and rejuvenating themselves," he said. "People are operating on assumed norms rather than actual norms."