C# - Convert DateTime to Long and Vice Versa

Story behind this post is when I started working with an existing MSSQL DB, I had to convert the DateTime to long since action auditing fields such as CreationTime, LastUpdated etc was stored as numeric.

eg, 20191028091320.

First of all, I don’t like storing DateTime in numeric format like above, which brings so much overhead during dealing with the same field, like querying based on date, formatting for displaying etc.

The way I handled these conversions given below,

DateTime to Long

1long.Parse(DateTime.UtcNow.ToString("yyyyMMddHHmmss")

Long to DateTime

The below code can handle 14 digits (eg. 20191028091320), 16 digits (eg. 2019102809132000 ) and 8 digits (eg. 20191028).

1private static DateTime? GetDateTimeFromInt(long? dateAsLong, bool hasTime = true)
2{
3    if (dateAsLong.HasValue && dateAsLong > 0)
4    {
5        if (hasTime)
6        {
7            // sometimes input is 14 digit and sometimes 16
8            var numberOfDigits = (int)Math.Floor(Math.Log10(dateAsLong.Value) + 1);
9
10            if (numberOfDigits > 14)
11            {
12                dateAsLong /= (int)Math.Pow(10, (numberOfDigits - 14));
13            }
14        }
15
16        if (DateTime.TryParseExact(dateAsLong.ToString(), hasTime ? "yyyyMMddHHmmss" : "yyyyMMdd",
17                                  CultureInfo.InvariantCulture,
18                                  DateTimeStyles.None, out DateTime dt))
19        {
20            return dt;
21        }
22    }
23
24    return null;
25}

function AskForFeedback() {

const [isHelpful, setIsHelpful] = React.useState();

let note;

if (isHelpful === "yes") {

note = (

<h5>

👊 that ⭐️ button on the official{" "}

href="https://github.com/Abhith/abhith.net"

target="_blank"

rel="noopener noreferrer"

GitHub repo

</a>

</h5>

<p>

Please leave a comment below! <br />

{ thank you ♥ } is enough

</p>

</div>

);

} else if (isHelpful === "no") {

note = (

<h4>Sorry about that!</h4>

<p> TODO(abhith): let me know how can I improve it?</p>

</div>

);

} else {

note = (

<h4>Your opinion matters</h4>

<p>Please share your thought about this article </p>

</>

);

}

return (

<h3>Was this article helpful?</h3>

<button

className="button is-success is-light"

onClick={() => setIsHelpful("yes")}

👍 Yes

</button>

<button

className="button is-warning is-light"

onClick={() => setIsHelpful("no")}

👎 No

</button>

</div>

{note}

</div>

);

}

C# - Convert DateTime to Long and Vice Versa

DateTime to Long

Long to DateTime

Was this article helpful?

Your opinion matters

Related Posts

Related Stories