Today I am writing again to bring you a library that will help us with the handling of dates in JavaScript, yes, as we all know the handling of dates in JavaScript is not very intuitive.
🤔 Why use dayjs?
Basically the justification for using dayjs is to simplify the handling of dates in JavaScript.
It is a fairly widespread library and which you have probably heard of already, it was presented a while ago as an alternative to Moment which is not recommended for use today, the main reason is the weight and the appearance of new alternatives that offer more modern and lighter solutions, dayjs is an example of this.
Moment
see more here
Dayjs
see more here
It is very light because it takes advantage of the Treeshaking since the library is fully extensible through plugins that we will add depending on the needs that arise, in this way we will only import the things we need.
🧪 Some examples
Now we will go to see some examples where its use would be justified compared to the native API, either for simplicity, readability or also to prevent possible errors.
We are going to review some of the most interesting functionalities that dayjs offers us.
🧹 Without plugins
Get difference in days between two dates
import dayjs from "dayjs";
dayjs(new Date(2020, 5, 10)).diff(new Date(2020, 5, 1), "day"); // output: 9
Check if the given date is valid or not
import dayjs from "dayjs";
dayjs("20").isValid(); // output: false
dayjs("2021-09-13").isValid(); // output: true
Get the number of days in the month
import dayjs from "dayjs";
dayjs("2021-09-13").daysInMonth() // output: 30
Add days, months, years, hours, minutes, seconds etc.
import dayjs from "dayjs";
dayjs("2021-09-13 20:09:09").add(20, "minute").format() // output: 2021-09-13T20:29:09+02:00
Subtract days, months, years, hours, minutes, seconds etc
import dayjs from "dayjs";
dayjs("2021-09-13 20:09:09").subtract(20, "minute").format() // output: 2021-09-13T19:49:09+02:00
⚡ Extending the functionality through plugins
RelativeTime
Get time difference in string format between current date and given date using Spanish locale
import dayjs from "dayjs";
import relativeTime from "dayjs/plugin/relativeTime";
import "dayjs/locale/es";
dayjs.locale("es");
dayjs.extend(relativeTime);
dayjs("2021-09-14T13:28:55.979Z").fromNow(); // example output: en 3 horas
WeekOfYear
Get week of year
import dayjs from "dayjs";
import weekOfYear from "dayjs/plugin/weekOfYear";
dayjs.extend(weekOfYear);
dayjs("2021-09-13T13:28:55.979Z").week(); // output: 38
IsSameOrAfter
Check if one date is equal to or greater than another
import dayjs from "dayjs";
import isSameOrAfter from "dayjs/plugin/isSameOrAfter";
dayjs.extend(isSameOrAfter);
// To use `year` granularity pass the second parameter
dayjs("2021-09-13").isSameOrAfter("2021-09-14", "year"); // output: true
MinMax
Get the highest date or the lowest date among the dates of an array
import dayjs from "dayjs";
import minMax from "dayjs/plugin/minMax";
dayjs.extend(minMax)
const maxDate = dayjs.max([
dayjs("2021-09-13"),
dayjs("2021-09-16"),
dayjs("2021-09-20")
])
const minDate = dayjs.min([
dayjs("2021-09-13"),
dayjs("2021-09-16"),
dayjs("2021-09-20")
])
maxDate.format() // output: 2021-09-20T00:00:00+02:00
minDate.format() // output: 2021-09-13T00:00:00+02:00
IsBetween
Check if the given date is within the indicated date range
import dayjs from "dayjs";
import isBetween from "dayjs/plugin/isBetween";
dayjs.extend(isBetween);
// To use `day` granularity pass the third parameter
dayjs("2010-10-21").isBetween(dayjs("2010-10-20"), dayjs("2010-10-25"), "day"); //output: true
// To use `year` granularity pass the third parameter
dayjs("2010-10-21").isBetween(dayjs("2010-10-20"), dayjs("2010-10-25"), "year"); //output: false
AdvancedFormat
Vitamin default formatting options
import dayjs from "dayjs";
import advancedFormat from "dayjs/plugin/advancedFormat";
dayjs.extend(advancedFormat);
dayjs("2021-09-14").format("Q Do k kk X x"); // output: 3 14th 24 24 1631570400 1631570400000
As can be seen in the examples above, the API is quite simple and readable, it seems to me without a doubt a great option if we need to solve some other complex function with dates in JavaScript.
For view more information go to official dayjs docs.
Thanks for reading me. 😊
Top comments (12)
Didn't heared of day.js before. Looks as light as you said.
Thanks, I'll keep it in mind for my future projects.
Thank you for your comment, I am glad that it is useful to you 🤗
It's nice to use but there's an outstanding issue in dealing with Daylight Savings Time raised a few months ago which meant we had to move to a different library. We now use Luxon, which works very well.
Oh thanks for your contribution 🎉 i was unaware of this topic 🙈
No problem, it's this one
github.com/iamkun/dayjs/issues/1260
but I see there have been a lot of similar issues raised since
I was quite happy with dayjs until I had to deal with issues with different timezones and DST. We started to migrate to luxon and luckily the API is mostly the same. I'd strongly recommend to consider this in your decision to use dayjs as it could help you from some hard to spot bugs.
Thank you for your contribution! 🤗
Isn't date-fns better? I didn't tested it out but I think that dayjs will include whole library in production build. In the other hand date-fns has is tree shakable.
Dayjs also supports tree-shaking, although date-fns is another great library for handling dates in JavaScript 🤗
We can write our own right.
It seems amazing, i'll definitely use in my next project. Thanks for sharing...
Thanks to you for your comment, good luck with that next project 😜