Write What You Know: Time Zones and Daylight Savings

Tonight I’m going to talk about time zones and daylight savings.  Before I dive into it, I want to take a quick moment to check in with you guys.


Hey there.  You doin’ okay?  Haven’t seen you around that much.  I get worried.


We’re about a third of the way through Blogtober and I think some of my posts this month are really good.  It’s a little bit stressful getting a blog entry posted each night, but it gets me in the frame of mind to write something daily.  That’s perfect preparation for next month.

I am a little weary writing all these blog posts, and it looks like you guys are a little tired of seeing one every night, too.  That’s okay!  They’ll still be here for later.  I have to remember that much of this Blogtober exercise is just to get me ready for next month.  You know what happens next month, right?  Bunches of us try to write 50,000 words in 30 days.

Do you know what else happens next month?  The time changes (for most of us) on November 4th!

And that leads perfectly into tonight’s subject, and is not a forced segue at all.


To write tonight’s post, I’m going to try something different.  I’m going to build this up as if it were a Q & A.


Q: Why are we discussing time zones tonight?  No one cares about time zones.

Okay, first of all?  Why all the attitude in the first question?  Second, lots of people care about time zones.  They’re called programmers, and they’re fantastic.

This was actually the first topic I came up with for this month.  I thought of it because at work, I seem to be the only person that seems to understand how time zones work.  Since I’m a writer, and we’re always told to write what we know, I thought I’d bring some of my expertise on the subject to you.

Also, it’s Wednesday night and I want a topic which won’t become a 2,000 word essay.  I want to have time to write something real tonight.


Q: I already know what time zones are.  There isn’t anything to discuss.

Dude, that wasn’t even a question.  You’d be terrible at Jeopardy.

But you’re right in that conceptually, they’re not that complicated.  Depending on where you live, your clock is going to be some number of hours or minutes off from someone that lives far enough east or west of where you are.  There isn’t that much to discuss.

Nevertheless, as the world has become smaller and smaller thanks to the internet, time zones affect our daily lives more and more.  Do you live on the West Coast and want to talk to your friend on the East Coast?  If you’re a good friend, you’re doing some math in your head when you look at the clock to make sure you’re not calling in the middle of the night.

More and more, I find that I have friends in New Zealand or the UK or other places far enough away that our hours of wakefulness barely overlap.


Q: Okay, so what’s your point?

My point is that as a programmer that deals with time sensitive information, it’s interesting.  Also, this is a subject that isn’t well represented in a lot of fiction.  If you’re going to put your stories in space, you might want to have an idea how time zones work.  I’m here to help you with some of the math, and to show you the kind of stuff I have to explain to my coworkers every damn day.


Q: I didn’t come here to learn math…

Let’s look at some examples of textual representations of time.


I looked at the clock on my computer, and that’s what I saw at a glance.  That’s what a lot of people see when they look at their watches or phones.  The problem is that it isn’t specific enough to be useful.  This example doesn’t even give AM or PM.  It’s non-information.

6:40 PM

Okay, that’s better.  But really, that’s still not enough to work with.  If you ask your bank when they plan to post a check to your account and they give you that information… well, there’s an implication they mean TODAY at 6:40PM.  But the implication itself is enough to show you that you need more than the hours on the clock to get exact time.  You need the date.

Oct 10, 6:40 PM

See, that’s still not enough…

Oct 10, 2018, 6:40 PM

You’d THINK that would be enough information.  Hell, some of the vendors we deal with which feed us time-stamped information think that’s enough.  But just like the hypothetical call to the bank, the only way for that information to be useful is to assume the time zone is the same as yours.  And you know what happens when you go assuming?  You make an ass out of you and some guy named Ming.

In Sacramento, the full time stamp would be:

Oct 10, 2018, 6:40 PM -07:00

That “-07:00” represents Pacific Daylight Time (PDT).  It means that during daylight savings, Sacramento is 7 hours less than Greenwich Mean Time (GMT).


Q: Why do we base our time zones around GMT?

Here, click this link.

I’m not really getting into the history of GMT and time zones as much as the functionality.  But basically, Greenwich was considered longitude 0, and things go from there.

Where it gets interesting is when you add daylight savings.


Q: I already know about daylight savings.  It’s Spring forward, Fall back.

Right.  And this year, “Fall back” occurs on November 4th at 2 AM.

Imagine that you have a spreadsheet and you’re tracking the mating habits of the rare crimson cricket, a nocturnal animal.  You have your low light cameras equipped and you’re making notes in a spreadsheet.  You’re dressed for a night op mission, but you’re watching insects fornicate like some kind of Jiminy Cricket voyeur.

In the first column of your spreadsheet, you’re keeping track of time.  I don’t know what you’re putting in the other columns.  Position?  Technique?  This is your weird science experiment, not mine.

Let’s say you’re doing this experiment on November 4th, 2018.  What does your spreadsheet look like as you cross into 3 AM?  Probably something like this:


02:15 AM Heavy chirping
02:35 AM More chirping, some slow dancing
02:45 AM Mild preening
02:55 AM Heavy preening
02:05 AM Significant wing action
02:15 AM Cuddle time

See what happened?  You’ve got two entries for 2:15 AM.  You can’t go straight from chirping to cuddle time!

Whatever the subject you’re recording, if it’s time sensitive data, and if it’s going into a database or spreadsheet, it’s very important that the time column is clear and doesn’t overlap.  In the Spring, you might be able to get away with the gap as you go straight from 1:59 AM to 3:00 AM.  But in the Fall?  It’s madness!


Q: Madness?  THIS. IS. SPARTA!!

Sparta, by the way, is in Central Daylight Time.  That’s 2 hours ahead of California, or -05:00 as of the time of this writing.  I’m talking about Sparta, Tennessee.

If you’re in California and you head east, the time on your clock is going to go up for every time zone you cross.  You’re also getting closer to GMT, which means the difference is going down.  California in October is -7 hours.  Utah is -6 hours.  Tennessee is -5 hours.

All of the following times are equivalent, referencing the exact same moment in time:

Oct 10, 2018, 6:40 PM -07:00
Oct 10, 2018, 7:40 PM -06:00
Oct 10, 2018, 8:40 PM -05:00
Oct 11, 2018, 1:40 AM +00:00

If you’re a programmer, you have to get used to this kind of thinking when it comes to dealing with time.  When you store the data in a database or spreadsheet, you either need to convert everything to GMT first, or you need to include the time zone with the data.  In SQL Server, the data type that does this for you is a DateTimeOffset.


Q: But I’m a writer, not a programmer.  I don’t care about databases or the fornicating habits of crickets.

That’s cool!  I’m a writer, too.  If you write sci-fi like me, you may want to consider time zones in your world building.

Look at it like this.  On Earth, we have a lot of languages [citation needed].

What do they speak on Klingon?  On Vulcan?  on Corellia?


Q: They speak Klingon, Vulcan, and Corellian.

That was a trick question because in practice, they mostly speak English.  But you get the idea.  If we want rich worlds that are believable, worlds so well drawn that it seems like we should be able to open the book and step right into them, shouldn’t we include details like different dialects?

Maybe we should consider the idea that even though it’s 6:40 PM on the ship orbiting the planet, it’s only 5:30 AM where the away team has landed.  If the away team isn’t thinking of it, I know damn well that the programmers on the ship are having to keep track of that information.  We have to.  It’s part of the job.


And that’s it!  You’re armed now!  Go forth and write a post about space programmers!

6 thoughts on “Write What You Know: Time Zones and Daylight Savings

    • Thank you! I had a lot of fun with this one. Michael Gallowglas sat across from me at Starbucks while I wrote it, and he kept asking me what I was giggling about.

      • Your enjoyment really shines through. I think that’s the best kind of writing – when you make yourself giggle while you do it! Or rub your hands with glee, or tear up at the havoc you’re causing. Keep it up!

  1. Pingback: The Firing of Chuck Wendig | Brian C. E. Buhl

  2. Oregon is considering being like Arizona and dropping the whole spring forward exercise. Keeping you informed.

    • California is considering the same thing. I’m all for it, even though it’s going to create extra work for me in the long run.

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