Store Date and Retrieve from Local Storage

Question

I stored a date to local storage like below.

JS:

var currentTime = new Date(); //get the current time.

//Clock in the time.
localStorage.time = currentTime;

When I try to retrieve it sometime later using...

var timeObj = new Date(localStorage.time);
var checkInDayOfMonth = timeObj.getUTCDate(); //returns 1-31 

the timeObj will not have the correct datetime, it instead appears to have the current time as if it's ignoring the parameters of the time I'm sending.

I'm using getUTCDate to get the day of the month. If the value of today is different than what is in storage I know it's a new day.

Opening Google Chrome Inspector reveals the date stored in localStorage in this format:

Wed Dec 11 2013 22:17:45 GMT-0800 (PST)

Is that not an acceptable format for the date constructor?

How can I store and retreive dates from localStorage correctly?

Solution 1

You can get it back as unix timestamp. Make sure to pass a number to Date constructor.

First, save. Add a + to new, to make this a timestamp.

localStorage.setItem('time', +new Date);

Then later retreive it, but pass the number to Date constructor:

new Date(parseInt(localStorage.getItem('time')));

Solution 2

Store the UNIX timestamp and then recreate the date object from that:

window.localStorage.time = new Date().getTime();

var date = new Date(parseInt(window.localStorage.time));

Comments

[Joseph Astrahan]

I tried doing this but I just get back NaN. I see the UNIX timestamp (the long series of numbers). It just won't seem to create the date object from it correctly. Any ideas? Did you actually test this idea?

[Joseph Astrahan]

I think my comment came out looking wrong, I meant to say I really like this idea (if it will work). Sometimes people post pseudo code. So was curious if that is what you were doing or if you have tried this idea and it verifiably worked?

[Joseph Astrahan]

The above has an error and does the current day before month, also month you need to say+1 since it returns 0-11

[Zlatko]

The retreival part needs a parseInt. Look at my answer?

[wizzwizz4]

@JosephAstrahan Many people wouldn't consider that to be an error; if you're being picky, it should be YYYY-MM-DD.

[Joseph Astrahan]

I wrote that comment years ago lol, I agree with what you said with my knowledge now