There are about 7.6 billion people in the world. And around 24% of them -- 1.8 billion -- are fasting from sunup to sundown. Every day. For an entire month.It's Ramadan, the holiest month of the Muslim calendar.

But what if you're not a Muslim -- just a caring, considerate person. Is there anything you should do so you don't come across as insensitive to your fasting friends in the US during Ramadan?Short answer: No. Long answer: No.

But you can earn some cool points if you follow these 10 tips:

1. You can totally eat in front of us ...

For the 30 days of Ramadan, Muslims around the world will abstain from eating and drinking during daylight hours. That doesn't mean you shouldn't carry on business as usual. (Just turn a deaf ear to our growling stomachs.)

2. ... but try not to schedule a work lunch

If you have to host a brown-bag, you should. But don't feel bad if we sit there, like a vegetarian friend at a churrascaria. Ditto for a happy-hour mixer. If your Muslim co-worker takes a pass, understand.

3. You don't have to fast with us ...

You can if you want to see what it feels like. But it's not going to hurt our feelings -- even if we're best friends.

4. ... but you can join us for Iftar

Iftar is the breaking of the fast after sundown. We like to make it a big communal meal. You should come.

5. You don't have to know when it begins ...

Ramadan isn't like Christmas or Thanksgiving, as in everyone knows exactly when it'll fall. It bounces around, because the Islamic calendar is lunar. When it begins depends on when the new moon is seen. That's why the precise dates change from year to year.

6. ... but please be a little flexible

How we determine when Ramadan begins is decidedly old-school: You have to physically see the moon (even though there are apps for that). That's why, if your co-worker says, "Starting tomorrow, can I start work early so I can leave sooner?" try to accommodate.

7. We'll still go for coffee with you ...

No, we can't drink. Not even water. But we'll walk with you if you want to take a break.

8. ... but we may keep our distance

One word: Halitosis. You try not eating or drinking for the entire day. That's why we're standing a foot away from you when we talk.

9. You can say 'Ramadan Mubarak' ...

There's no "war on Christmas"-level controversy surrounding the greeting (it means "Happy Ramadan"). Your Muslim co-worker will appreciate the thoughtfulness.

10. ... but please don't say, 'I should fast, too. I need to lose weight'

Ramadan's not about that. Plus, one of Ramadan's side effects is obesity (it's all that post-sundown overeating).