Cannot add minutes to date and convert to UK format.

[jonesin]

Hi,

I've spent ages trying piecemeal code but can only get this to work if I use current date and time.

I am reading a value from a config file where I do not control the date/time format.

Current format from config is this:

19-January-2018 04:00:03 PM

So to that date value, I'd like to add 500 minutes using a UK format so my result would look like:

20/01/2018 00:19:01

I'm sure this is trivial for most but really tired and can't seem to get this to work.

Many thanks!
J

[jdc2000]

What variable types are you storing this data in? Post the code you are using.

[jonesin]

hiya,

Ah, good question!!

Well, for the working one I'm simply:

dim dDate as datetime = DateTime.Now()
dDate = dDate.AddMinutes(500)
dDate .ToString('yyyyMMddhhmmss')  'change this later to UK

But when I read from config, my value is a string so let's say:

dim sMyDate as string = "19-January-2018 04:00:03 PM"

Cheers,
J

[jdc2000]

You would need to convert the string data you are reading in to a datetime variable. Then you can add the 500 minutes and convert the result back to a string in whatever format you need to write back out.

[jonesin]

Indeed. But I don't get how I'm meant to handle the - and AM/PM from just a string? Now it crashes .net to the point where I have to close it and open it again.

Do I need to chop this string up into separate variables? Seems a bit messy? This crashes:

Dim sMyDate As String = "19-January-2018 04:00:03 PM"
Dim dNewDate As DateTime = DateTime.ParseExact(sMyDate, "dd-MM-yyyy hh:mm:ss tt", CultureInfo.InvariantCulture)

[jdc2000]

Possibly useful links:

Convert String to datetime:

https://msdn.microsoft.com/en-us/lib...v=vs.110).aspx

Convert datetime to String:

https://msdn.microsoft.com/en-us/lib...v=vs.110).aspx

[jdc2000]

More useful links:

Add Minutes:

https://msdn.microsoft.com/en-us/lib...v=vs.110).aspx

https://msdn.microsoft.com/en-us/lib...nutes(v=vs.71)

Add Hours:

https://msdn.microsoft.com/en-us/lib...v=vs.110).aspx

[jmcilhinney]

Dates don't have formats. They are binary values; just numbers. If you want to see a date in a particular format then you need a String representation of a Date. Basically, what you need to do is take the String you have to start with, convert that to a Date, perform the appropriate arithmetic with that, then convert the result to a String. If you know for a fact that your initial String is a valid representation of a date then call Date.ParseExact to convert it to a Date. If you're not sure, call TryParseExact. You can then use the code that you have in the first snippet in post #2, except you have to assign the result of ToString somewhere.

[techgnome]

Indeed. But I don't get how I'm meant to handle the - and AM/PM from just a string? Now it crashes .net to the point where I have to close it and open it again.

Do I need to chop this string up into separate variables? Seems a bit messy? This crashes:

Dim sMyDate As String = "19-January-2018 04:00:03 PM"
Dim dNewDate As DateTime = DateTime.ParseExact(sMyDate, "dd-MM-yyyy hh:mm:ss tt", CultureInfo.InvariantCulture)

That's because the format you passed ParseExact doesn't match the date....

        Dim sMyDate As String = "19-January-2018 04:00:03 PM"
        Dim dNewDate As DateTime = DateTime.ParseExact(sMyDate, "dd-MMMM-yyyy hh:mm:ss tt", CultureInfo.InvariantCulture)

You have a complete month name... NOT a two digit value, so it needs to be MMMM.


-tg

[jmcilhinney]

Hmmm... it appears that I managed to overlook post #5.