Problem deserializating JSON Date in C# - adding 2 hours

Question

We are having such a nasty problem when deserializating a JSON date to a C# DateTime.

The code is:

JavaScriptSerializer serializer = new JavaScriptSerializer();
jsonTrechos = jsonTrechos.Replace("/Date(", "\\/Date(").Replace(")/", ")\\/");
Trecho[] model = serializer.Deserialize<Trecho[]>(jsonTrechos);

The jsonTrechos is a string of json2.js's JSON.stringify();.

Problem is: the deserialization works, bur all dates of the Trechos objects are added with 2 hours.

My timezone is Brazil (UTC -3) and we're under daylight savings (so we're currently on UTC -2), if it has anything to do. I guess that perhaps localization and timezones may be playing a part on this and if they really are, I have no idea on how to fix it.

Btw, those Replaces are there so the serializer can recognize the "\/Date(number)\/" format. — viniciushana
– viniciushana, Commented Nov 29, 2010 at 14:05
I recommend using UTC dates internally unless there are compelling reasons not to. And in the cases where you need non-UTC dates a simple local date doesn't work well either, but you typically need something more complex taking care of timezones. — CodesInChaos
– CodesInChaos, Commented Nov 29, 2010 at 14:31

Razzie · Accepted Answer · 2010-11-29 14:20:50Z

13

This is documented in the MSDN:

Date object, represented in JSON as "/Date(number of ticks)/". The number of ticks is a positive or negative long value that indicates the number of ticks (milliseconds) that have elapsed since midnight 01 January, 1970 UTC.

Try calling DateTime.ToLocalTime() and see if you get the correct date for you.

answered Nov 29, 2010 at 14:20

Razzie

31.3k12 gold badges67 silver badges82 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Chris S Over a year ago

@scardazzi stackoverflow.com/questions/1263732/… has some info about parsing too which I've been stung with before

Scott Over a year ago

This got me on the right track. I am using Json.NET to deserialize some JSON and had to set my DateTimeZoneHandling property to DateTimeZoneHandling.Local.

casperOne · Accepted Answer · 2010-11-29 14:13:34Z

7

I would strongly recommend working with the Json.NET library. Quite frankly, the JSON serializers (and there are multiple ones) in the .NET framework are all quirky in some way, especially when it comes to serializing dates.

Json.NET is the only library that I've seen that handles them (and JSON in general) consistently and without problem for other consumers.

answered Nov 29, 2010 at 14:13

casperOne

74.7k19 gold badges189 silver badges262 bronze badges

2 Comments

viniciushana Over a year ago

Makes sense, I've played with it a little and I liked it. I'll check it out, thanks!

Justin Over a year ago

This is way better than the javascriptserializer class in terms of date handling and performance, thanks!!

Chris S · Accepted Answer · 2010-11-29 14:23:49Z

2

The dates specified for JSON are UTC, and as you've mentioned you're using daylight savings so +2 hours makes sense. Ideally you should be working with UTC date times anyway, as it removes the headaches of daylight savings (or in this case, it's added to it) and allows for global hosting.

answered Nov 29, 2010 at 14:23

Chris S

65.6k53 gold badges225 silver badges240 bronze badges

1 Comment

viniciushana Over a year ago

You're right, it'd be the best to do this, however it'll take such a long time to adapt this system to this. But thanks for the advice!

Robert · Accepted Answer · 2011-03-07 22:00:06Z

1

"Javascript dates are calculated in milliseconds from 01 January, 1970 00:00:00 Universal Time (UTC) with a day containing 86,400,000 milliseconds" (Excerpt from W3schools). So you want to convert it to your local timezone.

TimeZoneInfo.ConvertTimeFromUtc(yourDateToConvert, TimeZoneInfo.Local)

answered Mar 7, 2011 at 22:00

Robert

5208 silver badges17 bronze badges

Collectives™ on Stack Overflow

Problem deserializating JSON Date in C# - adding 2 hours

4 Answers 4

2 Comments

2 Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

2 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related