<
script
src
=
"//cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.4.0/
↩
moment-timezone.min.js"
></
script
>
If you’re working with Node, you can install Moment.js with
npm install --save
moment-timezone
and then reference it from your script with
require
:
const
moment
=
require
(
'moment-timezone'
);
Moment.js is large and robust, and chances are, if you need to manipulate dates, it
has exactly the functionality you need. Consult its
for more
information.
A Practical Approach to Dates in JavaScript
Now that we have the basics out of the way, and you have Moment.js available, we’re
going to take a slightly different approach to covering this information. An exhaustive
coverage of the methods available on the
Date
object would be dry and not very use‐
ful to most people. Furthermore, if you need that reference,
is exhaustive and well-written.
Instead, this book will take a more cookbook-based approach and cover the common
date processing needs that people have, and use
Date
and Moment.js where appropri‐
ate.
Constructing Dates
We’ve already covered the construction options available to you with JavaScript’s
Date
object, which are, for the most part, adequate. Whenever you construct a date
without an explicit time zone, you have to think about what time zone is being used,
which is going to be dependent on where the date is being constructed. This has trip‐
ped up many a beginner in the past: they use the same date code on a server in
Arlington, Virginia, as they use in a user’s browser connecting from Los Angeles, Cal‐
ifornia, and they are surprised when the dates are off by three hours.
Constructing Dates on the Server
If you’re constructing dates on the server, I recommend always either using UTC or
explicitly specifying the time zone. With today’s cloud-based approach to application
development, the same code base could be running on servers all over the world. If
you’re constructing local dates, you’re asking for trouble. If you are able to use UTC
dates, you can construct them with the
Date
object’s
UTC
method:
const
d
=
new
Date
(
Date
.
UTC
(
2016
,
4
,
27
));
// May 27, 2016 UTC
222 | Chapter 15: Date and Time
