Android Question Comparing 2 date time values in b4A and displaying date in dd-Mon-yyyy hh:mm AMPM format - reg.

beelze69 · Feb 21, 2022

Hi,

I have the following doubts with regard to handling date and time in b4A:

1) I have to perform the following validation:

If input Date=System Date then
the input time should not be within 1 hour from the system time
i.e. if the input date equals the system date and the current time is 11:30 am then the input time should
be greater than or equal to 12:30 pm...

For date comparison we can use the
DateTime.Date(lnginputDate)=DateTime.Date(lngsystemDate)
{Where lnginputDate=Datetime.DateParse(inputdate)
and lngSystemDate=Datetime.DateParse(DateTime.Now) }

For hour difference we can use

Dim PerDiff as Period
PerDiff=DateUtils.PeriodBetween(Datetime.DateParse(inputDate),DateTime.now)

Log("Difference in Minutes:" & Perdiff.Minutes)

However, I have my input date as a string in dd-mm-yyyy hh:mm format ,for example: 21-02-2022 11:10

And DateTime.DateFormat = "dd-MM-yyyy hh:mm" is not acceptable.

So how can we do the above comparison in such case ?

2) In SQLLITE (and via DateTime/DateUtils), how does one display the date 21-02-2022 21:05 as
as 21-Feb-2022 9:05 pm ?

Require some assistance on the above.

Thanks..

Erel · Feb 21, 2022

Please use [code]code here...[/code] tags when posting code.

beelze69 said:
And DateTime.DateFormat = "dd-MM-yyyy hh:mm" is not acceptable.

Why not?

KMatle · Feb 21, 2022

You decide (by code) what you store and compare, but you HAVE to. So no issue here (except we don't get the point).

Formatting date/time (you can combine what you like):
https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html

beelze69 · Feb 21, 2022

Erel said:
Please use [code]code here...[/code] tags when posting code.

Why not?

I am attaching some code which I have written in which I tried to use the dd-mm-yyyy hh:mm format but it gives me the Unparseable Date error..

B4X:

    Dim cs As CSBuilder
    Dim PerDiff As Period
    Dim constructedInputDateTime As String
    Dim dSelectedDate As Long
    Dim dSystemDate As Long
    DateTime.DateFormat = "dd-MM-yyyy hh:mm"
    'I have separate labels for storing the Date part and the time part and hence I am
    'concatenating them below
    constructedInputDateTime=lblDate.Text & " " &  lblHour.Text & ":" & lblMinute.Text
    dSelectedDate = DateTime.DateParse(constructedInputDateTime)
    dSystemDate = DateTime.Dateparse(  DateTime.Now)'
    Log("Your Selected Date is " & DateTime.Date(dSelectedDate) & " " & "Current Date is " & DateTime.Date(dSystemDate))
    If DateTime.Date(dSelectedDate) < DateTime.Date(dSystemDate) Then
     
        Dialog.Title = cs.Initialize.Size(20).Append("Message").PopAll
        Wait For (Dialog.Show( "Appointment Date cannot be before the System Date ..",  "Ok",  "", "")) Complete (unUsedReturnValue As Int)
     
    End If
    If DateTime.Date(dSelectedDate) = DateTime.Date(dSystemDate) Then
        Log("CURRENT DATE IS SELECTED")
        PerDiff=DateUtils.PeriodBetween(DateTime.DateParse(constructedInputDateTime),DateTime.Now)
        Log("Difference in days:" & PerDiff.Days)
        Log("Difference in Minutes:" & PerDiff.Minutes)
        Log("difference in seconds :" & PerDiff.Seconds)
    End If

I am getting the following error:

B4X:

Error occurred on line: 422 (pg1)
java.text.ParseException: Unparseable date: "21-02-2022 19:45"
    at java.text.DateFormat.parse(DateFormat.java:362)
    at anywheresoftware.b4a.keywords.DateTime.DateParse(DateTime.java:148)
    at b4a.example.pg1$ResumableSub_btnConfirmScheduling_Click.resume(pg1.java:590)
    at b4a.example.pg1._btnconfirmscheduling_click(pg1.java:538)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
    at anywheresoftware.b4a.BA$2.run(BA.java:387)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:201)
    at android.app.ActivityThread.main(ActivityThread.java:6823)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

Also requesting for answer to the 2nd point viz.

2) In SQLLITE (and via DateTime/DateUtils), how does one display the date 21-02-2022 21:05 as
as 21-Feb-2022 9:05 pm ?

Thanks..

Spavlyuk · Feb 21, 2022

Use capital letters for parsing 24h formats.

B4X:

DateTime.DateFormat = "dd-MM-yyyy HH:mm"

You can find all the format options here: https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Mahares · Feb 21, 2022

As @Spavlyuk mentioned, if you store your date as ticks in the SQLite, you can use:

B4X:

DateTime.DateFormat = "dd-MM-yyyy HH:mm" 'for 24 hr format

If you want to use AM/PM format the format must be:

B4X:

DateTime.DateFormat = "dd-MM-yyyy hh:mm a"

beelze69 said:
2) In SQLLITE (and via DateTime/DateUtils), how does one display the date 21-02-2022 21:05 as
as 21-Feb-2022 9:05 pm ?

As for question#2: If you stored your date as ticks using the 24 hr format and you want to display your data like 21-Feb-2022 9:05 pm, you need to change your date format before displaying the information to this format:

B4X:

DateTime.DateFormat = "dd-MMM-yyyy hh:mm a"

beelze69 · Feb 21, 2022

Spavlyuk said:
Using capital letters for parsing 24h formats.

B4X:

DateTime.DateFormat = "dd-MM-yyyy HH:mm"

You can find all the format options here: https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Hi !,

I modified the code accordingly... I also found an issue in the line dSystemDate = DateTime.Dateparse( DateTime.Now) on my above code and corrected it ..
Modified code is :

B4X:

Dim cs As CSBuilder
    Dim PerDiff As Period
    Dim constructedInputDateTime As String
    Dim constructedSystemDateTime As String
    Dim dSelectedDate As Long
    Dim dSystemDate As Long
    DateTime.DateFormat = "dd-MM-yyyy HH:mm"
    Log("Current Date and Time from vide click button is :")
    Log(DateTime.Date( DateTime.Now))
    constructedInputDateTime=lblDate.Text & " " &  lblHour.Text & ":" & lblMinute.Text
    dSelectedDate = DateTime.DateParse( constructedInputDateTime)
    constructedSystemDateTime=DateTime.Date( DateTime.Now)
    dSystemDate = DateTime.DateParse(  constructedSystemDateTime)
    Log("Your Selected Date is " & DateTime.Date( dSelectedDate) & " " & "Current Date is " & DateTime.Date(dSystemDate))
    If DateTime.Date(dSelectedDate) < DateTime.Date(dSystemDate) Then
       
        Dialog.Title = cs.Initialize.Size(20).Append("Message").PopAll
        Wait For (Dialog.Show( "Appointment Date cannot be before the System Date ..",  "Ok",  "", "")) Complete (unUsedReturnValue As Int)
       
    End If
    If DateTime.Date(dSelectedDate) = DateTime.Date(dSystemDate) Then
        Log("CURRENT DATE IS SELECTED")
        PerDiff=DateUtils.PeriodBetween(DateTime.DateParse(constructedInputDateTime),DateTime.Now)
        Log("Difference in days:" & PerDiff.Days)
        Log("Difference in Minutes:" & PerDiff.Minutes)
        Log("difference in seconds :" & PerDiff.Seconds)
    End If

However, I am now getting the following error:

B4X:

Error occurred on line: 429 (pg1)

java.lang.NumberFormatException: For input string: "21-02-2022 11:50"

    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)

    at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)

    at java.lang.Double.parseDouble(Double.java:538)

    at b4a.example.pg1$ResumableSub_btnConfirmScheduling_Click.resume(pg1.java:617)

    at b4a.example.pg1._btnconfirmscheduling_click(pg1.java:538)

    at java.lang.reflect.Method.invoke(Native Method)

    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)

    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)

    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)

    at java.lang.reflect.Method.invoke(Native Method)

    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)

    at anywheresoftware.b4a.BA$2.run(BA.java:387)

    at android.os.Handler.handleCallback(Handler.java:873)

    at android.os.Handler.dispatchMessage(Handler.java:99)

    at android.os.Looper.loop(Looper.java:201)

    at android.app.ActivityThread.main(ActivityThread.java:6823)

    at java.lang.reflect.Method.invoke(Native Method)

    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

Requesting for help...

Thanks..

Mahares · Feb 21, 2022

When you compare dates, do not compare the string dates. You can parse the string date, but compare dates in ticks. For instance:
instead of:

B4X:

If DateTime.Date(dSelectedDate) < DateTime.Date(dSystemDate) Then

You should use:

B4X:

If dSelectedDate < dSystemDate Then

The same applies if you are comparing any additional dates in your code.
You may also want to log the hours in the latter part of your code: You are logging days, minutes but not hours

beelze69 · Feb 22, 2022

Mahares said:
When you compare dates, do not compare the string dates. You can parse the string date, but compare dates in ticks. For instance:
instead of:

B4X:

If DateTime.Date(dSelectedDate) < DateTime.Date(dSystemDate) Then

You should use:

B4X:

If dSelectedDate < dSystemDate Then

The same applies if you are comparing any additional dates in your code.
You may also want to log the hours in the latter part of your code: You are logging days, minutes but not hours

Mahares · Feb 22, 2022

beelze69 said:
. Hence I am comparing only the Date part of the ticks values with
DateTime.Date(dSelectedDate) and DateTime.Date(dSystemDate)

No. Those dates are a combination of date and time because your Dateformat isateTime.DateFormat = "dd-MM-yyyy HH:mm"
Look at the diffeence between these two below formats:

B4X:

DateTime.DateFormat = "dd-MM-yyyy"
    DateTime.TimeFormat = "HH:mm"
    Log(DateTime.Date(DateTime.Now))    '21-02-2022
    Log(DateTime.time(DateTime.Now))

B4X:

 DateTime.DateFormat = "dd-MM-yyyy HH:mm"
    Log(DateTime.Date(DateTime.Now))  '21-02-2022 20:09
    Log(DateTime.time(DateTime.Now))

If you are still: 'Requesting for help..' , you are better off put a little project together and upload it.

beelze69 · Feb 22, 2022

Hi Mahares,

Thanks a lot for the guidance.

I think I have resolved it, albeit in a very crude way.

For one, I am changing the date format to include and exclude the time components and storing the appropriate string values extracted via DateParse into different variables.

Then I store the ticks values of all these string variables into corr. long variables.

Then I do the comparison using only the ticks as you suggested..

Wondering, if there is a better way to do this..

Please see below code:

B4X:

Dim cs As CSBuilder
    Dim PerDiff As Period
    Dim constructedInputDate As String
    Dim constructedSystemDate As String
    Dim constructedInputDateTime As String
    Dim constructedSystemDateTime As String
    Dim dSelectedDate As Long
    Dim dSelectedDateWithTime As Long
    Dim dSystemDate As Long
    Dim dSystemDateWithTime As Long
    DateTime.DateFormat = "dd-MM-yyyy HH:mm"
    Log( DateTime.Date(DateTime.Now))
    constructedInputDateTime=lblDate.Text & " " &  lblHour.Text & ":" & lblMinute.Text
    dSelectedDateWithTime = DateTime.DateParse(constructedInputDateTime)
    constructedSystemDateTime=DateTime.Date(DateTime.Now)
    dSystemDateWithTime = DateTime.DateParse(  constructedSystemDateTime)
    Log("Your Selected Date is " & DateTime.Date(dSelectedDateWithTime) & " " & "Current Date is " & DateTime.Date(dSystemDateWithTime))
    'now string only the date part into corr. string variables..
    constructedInputDate=lblDate.Text
    DateTime.DateFormat="dd-MM-yyyy"
    constructedSystemDate=DateTime.Date(DateTime.Now)
    'now store the ticks value of only the Date Part into corr long variables before you compare
    dSelectedDate=DateTime.DateParse(constructedInputDate)
    dSystemDate=DateTime.DateParse(constructedSystemDate)
    If  dSelectedDate < dSystemDate Then
     
        Dialog.Title = cs.Initialize.Size(20).Append("Message").PopAll
        Wait For (Dialog.Show( "Appointment Date cannot be before the System Date ..",  "Ok",  "", "")) Complete (unUsedReturnValue As Int)
     
    End If
    If dSelectedDate = dSystemDate Then
        Log("CURRENT DATE IS SELECTED")
        PerDiff=DateUtils.PeriodBetweenindays(dSystemDateWithTime,dSelectedDateWithTime)
 
        Log("Difference in days:" & PerDiff.Days)
        Log("Difference in Hours:" & PerDiff.Hours)
        Log("Difference in Minutes:" & PerDiff.Minutes)
        Log("difference in seconds :" & PerDiff.Seconds)
     
    End If

beelze69 · Feb 22, 2022

Spavlyuk said:
Using capital letters for parsing 24h formats.

B4X:

DateTime.DateFormat = "dd-MM-yyyy HH:mm"

You can find all the format options here: https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Thanks Spavlyuk for pointing that out...

beelze69 · Feb 22, 2022

Erel said:
Please use [code]code here...[/code] tags when posting code.

Why not?

Hi Erel,

Thanks.. I have posted my final code post chat with Mahares...
Please guide on any better way to do this (rather than changing the DateFormat everytime, extracting out the Ticks Part via DateParse and then doing the comparison of the Ticks - the way I have done)..

Thanks...

Erel · Feb 22, 2022

Using DateParse to convert the date string to ticks values is the correct way to do it.

beelze69 · Feb 22, 2022

Erel said:
Using DateParse to convert the date string to ticks values is the correct way to do it.

Thanks Erel

AnandGupta · Feb 28, 2022

Hi @beelze69

If you want (but not needed) to compare date (only date) in string, then use format

B4X:

       DateTime.DateFormat = "yyyyMMdd"

This way dates will be correctly sorted for comparision. We do it in Xbase++/Clipper as there is no ticks support here.

beelze69 · Mar 1, 2022

AnandGupta said:
Hi @beelze69

If you want (but not needed) to compare date (only date) in string, then use format

B4X:

DateTime.DateFormat = "yyyyMMdd"

This way dates will be correctly sorted for comparision. We do it in Xbase++/Clipper as there is no ticks support here.

Wow !

You still use Clipper ? ... Wonderful Programming Language.. But I never really got to use it fully... Was totally into Foxpro ... The Foxpro guys gave one Compiler to create standalone exe but it was WAY TOO BULKY...

I tried Clipper way back in the 90s (under DOS environment) [before Windows 3.1]...

Thanks for that info.. on Date format.. .. Will try it out...

AnandGupta · Mar 1, 2022

beelze69 said:
Wow !

You still use Clipper ? ... Wonderful Programming Language.. But I never really got to use it fully... Was totally into Foxpro ... The Foxpro guys gave one Compiler to create standalone exe but it was WAY TOO BULKY...

I tried Clipper way back in the 90s (under DOS environment) [before Windows 3.1]...

Thanks for that info.. on Date format.. .. Will try it out...

Well I learnt Basic (Original) , Fortran and Cobol. Then worked on BasicA, GWBasic, dBase II, dBase III+, FoxBase, FoxPro, Clipper 87, Clipper 5, Xbase++, VB.Net and now Java and B4X. For network I worked on Novell Netware and Ms Client/Server. Also had some hands on Linux but very little, as all our clients used Windows and we had to make products for them.

In nearly all languages I worked, I made complete application products which were sold by our company.

Mahares · Mar 1, 2022

AnandGupta said:
DateTime.DateFormat = "yyyyMMdd"

To carry Anand's post further, you can actuall use yyyy-MM-dd or yyyy/MM/dd or yyyy.MM.dd. It looks like a real date and you can still sort by it, especially if you are using it in a SQL query.

beelze69 · Mar 2, 2022

AnandGupta said:
Well I learnt Basic (Original) , Fortran and Cobol. Then worked on BasicA, GWBasic, dBase II, dBase III+, FoxBase, FoxPro, Clipper 87, Clipper 5, Xbase++, VB.Net and now Java and B4X. For network I worked on Novell Netware and Ms Client/Server. Also had some hands on Linux but very little, as all our clients used Windows and we had to make products for them.

In nearly all languages I worked, I made complete application products which were sold by our company.

That's great..

Is Clipper still used ? I mean.. now that DOS is gone... You have Clipper apps still running ?

Mahares said:
To carry Anand's post further, you can actuall use yyyy-MM-dd or yyyy/MM/dd or yyyy.MM.dd. It looks like a real date and you can still sort by it, especially if you are using it in a SQL query.

Thanks .. will try it out...

Android Question Comparing 2 date time values in b4A and displaying date in dd-Mon-yyyy hh:mm AMPM format - reg.

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