system.text.json + azure functios + cosmos db

I’m not sure if it’s really an issue or normal behavior. But I have the following situations:

public DateTimeOffset Date1 { get; set; } = DateTimeOffset.Now;
public DateTimeOffset Date2 { get; set; } = DateTimeOffset.UtcNow;
public DateTime Date3 { get; set; } = DateTime.Now;
public DateTime Date4 { get; set; } = DateTime.UtcNow;

And it is saving as follows in the cosmos:

"date1": "2021-02-01T12:28:55.845-03:00",
"date2": "2021-02-01T15:28:55.962+00:00",
"date3": "2021-02-01T12:28:55.963-03:00",
"date4": "2021-02-01T15:28:55.963Z",

I’m trying to use the date functions of the cosmos (DateTimeDiff), but it only accepts the last format.

Shouldn’t the cosmos save exclusively in the last format, which is what it accepts?

[drma-dev]

Thank you. Anyway, I’m using the example that works: public DateTime Date4 {get; set; } = DateTime.UtcNow

[ealsur]

Shouldn’t the cosmos save exclusively in the last format, which is what it accepts?

What do you mean by accept? Are you getting errors with the other formats?

This is part of Newtonsoft.Json serialization of datetimes: https://www.newtonsoft.com/json/help/html/DatesInJSON.htm

You could configure the default settings to use a particular format, decorate the class to use a custom converter. From the SDK perspective, this is a string field and it is sent on the wire to the backend. There is no validation that should happen on the SDK. If the backend can store the data, then it’s valid.

Is the problem that you are afterwards executing queries? If so, there is a doc talking about it: https://docs.microsoft.com/en-us/azure/cosmos-db/working-with-dates#storing-datetimes

But this is not a requirement, you could be storing dates in any format because they might be later on consumed by a reader that does not execute queries or something like that.