Converting Nanoseconds to Datetime

Question

I'm having a little trouble converting nanoseconds to DateTime so i can use the Google Fit API (https://developers.google.com/fit/rest/v1/reference/users/dataSources/datasets/get)

Dataset identifier that is a composite of the minimum data point start time and maximum data point end time represented as nanoseconds from the epoch. The ID is formatted like: "startTime-endTime" where startTime and endTime are 64 bit integers.

I was able to convert from datetime to Nanoseconds this way

DateTime zuluTime = ssDatetime.ToUniversalTime();
DateTime unixEpoch = new DateTime(1970, 1, 1);
ssNanoSeconds = (Int32)(zuluTime.Subtract(unixEpoch)).TotalSeconds + "000000000";

But now i need to convert nanoseconds to DateTime. How can i do it?

`Ticks` resolution is 100 nanoseconds. You can add it with `AddTicks` method. — Soner Gönül, Dec 07 '15 at 12:11
Nanoseconds since when? 1970-01-01T00:00:00Z or some time else? — Jon Hanna, Dec 07 '15 at 12:22

Sergii Zhevzhyk · Accepted Answer · 2015-12-07T12:44:49.950

8

Use AddTicks method. Don't forget to divide nanoseconds by 100 to get ticks.

long nanoseconds = 1449491983090000000;
DateTime epochTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
DateTime result = epochTime.AddTicks(nanoseconds / 100);

edited Dec 07 '15 at 12:44

answered Dec 07 '15 at 12:26

Sergii Zhevzhyk

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Perfect28 · Answer 2 · 2015-12-07T12:27:31.753

2

Ticks property represents 100 nanoseconds. So how about :

 var ssNanoSeconds = ((zuluTime.Subtract(unixEpoch)).Ticks / 100)

From nanoseconds to DateTime

 DateTime dateTime = new DateTime(1970, 1, 1).AddTicks(nanoSeconds * 100) ;

edited Dec 07 '15 at 12:27

answered Dec 07 '15 at 12:11

Perfect28

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Your `new DateTime` is starting with `DateTime.MinValue`, not the unix epoch. – Jon Hanna Dec 07 '15 at 12:25
Also the nanoSeconds in the first line need to be multiplied by 100 and divided in the second example. so: `..(zuluTime.Subtract(unixEpoch)).Ticks * 100 ..` and `.AddTicks(nanoSeconds / 100)` – Robert Sirre Dec 17 '18 at 14:16

Sandip Parajuli · Answer 3 · 2023-01-03T04:51:48.613

To convert nanoseconds to a DateTime object, you can do the following:

Divide the nanoseconds value by 1,000,000,000 to get the equivalent number of seconds. Create a DateTime object representing the Unix epoch (January 1, 1970). Add the number of seconds to the Unix epoch to get the desired DateTime object.

long nanoseconds = 1234567890123; // nanoseconds value to convert

// Divide the nanoseconds value by 1,000,000,000 to get the equivalent number of seconds
int seconds = (int)(nanoseconds / 1000000000);

// Create a DateTime object representing the Unix epoch (January 1, 1970)
DateTime unixEpoch = new DateTime(1970, 1, 1);

// Add the number of seconds to the Unix epoch to get the desired DateTime object
DateTime datetime = unixEpoch.AddSeconds(seconds);

Note that this will only work correctly if the nanoseconds value is within the range of values that can be represented by a DateTime object (approximately 292 million years before or after the Unix epoch). If the nanoseconds value is outside of this range, the resulting DateTime object will not be accurate.

Converting Nanoseconds to Datetime

3 Answers3