Converting Timespan to DateTime in C#

Question

I am reading Excel worksheet data using C# and Microsoft.Office.Interop. The sheet contains some date values. When I am trying to read that value it is just giving the number (probably TimeSpan). I am having problem converting this number into DateTime.

Below is the code:

TimeSpan ts = TimeSpan.Parse(((Range)ws.Cells[4, 1]).Value2.ToString());

Where ws is Excel.WorkSheet.

Can anybody explain how should I convert this number (TimeSpan) into DateTime?

Thanks for sharing your valuable time.

It could be giving you ticks which the datatime has a contructor for. — rerun, Jan 25 '11 at 07:50

score 9 · Accepted Answer · answered Jan 25 '11 at 07:52

9

You could do the following

double d = double.Parse(((Range)ws.Cells[4, 1]).Value2.ToString());

DateTime conv = DateTime.FromOADate(d);

answered Jan 25 '11 at 07:52

Dimi Takis

4,924
3
29
41

Verified with the OP's test data of 40269 = Apr 1 2010: `var when = DateTime.FromOADate(40269);` – Marc Gravell Jan 25 '11 at 07:56
Greco -- did you change your name? I'll update my answer if so :) – Tim Barrass Apr 13 '12 at 18:54

score 9 · Answer 2 · edited May 06 '11 at 16:38

9

Use the following:

DateTime dt = new DateTime().Add( TimeSpan.FromMilliseconds( 1304686771794 ) )

edited May 06 '11 at 16:38

GSerg

76,472
17
159
346

answered May 06 '11 at 13:22

Ardian

91
1
1

score 6 · Answer 3 · answered Jan 25 '11 at 07:51

6

It all depends on what the number looks like ;p That is typically the offset in some interval, into some epoch - for example seconds since 1 Jan 1970. So try, for example:

var when = new DateTime(1970,1,1).AddSeconds(number);

and then try AddMilliseconds(number), AddTicks(number) etc until the date matches.

answered Jan 25 '11 at 07:51

Marc Gravell

1,026,079
266
2,566
2,900

Thanks Marc for your quick reply. Can you please tell me what should i consider if i m getting 40269 for Apr/1/2010. – IrfanRaza Jan 25 '11 at 07:54
@IrfanRaza - in that case @Greco has the answer; `var when = DateTime.FromOADate(40269);` – Marc Gravell Jan 25 '11 at 07:55

score 2 · Answer 4 · answered Jan 25 '11 at 08:00

This is just icing: Excel represents dates as OLE automation dates. These values are floating point numbers, the integer part of which is the number of days after midnight, 30 Dec 1899. Or before, if it's negative. Greco's answer gives you the best way to convert :)

Converting Timespan to DateTime in C#

4 Answers4