Adding minutes to a time field

[Larry Gordon]

Happy New Year!

I have a browse with containing the following fields: 'Start_Time', 'End_Time' and 'Minutes'. (The Time fields are in fact Time fields and the Minutes is a Numeric field).

What I want to do is enter a date and time into the Start_Time and then in the next field enter an amount of minutes, typically two digits in length. I then want the minutes field to be added to the Start_Time and populate the End_Time field accordingly. I have been trying to do it in Field Rules but without success.

I have searched the board but I can't find any previous examples of adding minutes to time fields.

Any help would be greatly appreciated.

[Stan Mathews]

Re: Adding minutes to a time field

Date/time addition is performed by adding seconds to the value, not minutes. Your calculation should multiply the minutes by 60.

Hidden in the documentation under Date and Time Functions.

[Tom Cone Jr]

Re: Adding minutes to a time field

For the mathematically inclined this is akin to the principle of the lowest common denominator in long division.

[Larry Gordon]

Re: Adding minutes to a time field

Thanks very much for the replies. I had already found the 'Date & Time Addition' section in the Help docs but didn't get too far with it as there is no explanation to the code, e.g.:

t1 = now()
? t1
= 10/19/2005 11:07:07 53 am
t2 = ctodt("10/20/05 12:07:07 53 am")
? t2
= 10/20/2005 12:07:07 53 am
t2 = t2 + 60
? t2
= 10/20/2005 12:08:07 53 am
t1 = t1 + 0.47
? t1
= 10/19/2005 11:07:08 00 am

I'm not interested in the 'now()' function above so I'm guessing I can replace that with my 'Start_time' field, but after that - I'm lost. Is there anywhere I can find a fuller explanation of the above sample code?

[Tom Cone Jr]

Re: Adding minutes to a time field

this code runs in the interactive window

t1 = now()   ' assign a date time value to the variable t1; check docs for meaning of NOW() function
? t1        ' display the value using the question mark command
= 10/19/2005 11:07:07 53 am     ' the equals sign shows you what t1 contains;  i.e.  its value
                                      ' check docs for discussion of datetime datatypes.  
                                      ' a datetime value contains a date, an hour, a minute, a second values.  AND
                                      ' in this case the "53" represents 53 hundredths of a second

t2 = ctodt("10/20/05 12:07:07 53 am")     ' convert a character string to a datetime value and assign it to t2
? t2
= 10/20/2005 12:07:07 53 am                 ' as before, display the datetime value in t2

t2 = t2 + 60          ' add 60 seconds to the datetime value in t2
? t2
= 10/20/2005 12:08:07 53 am                 ' as before, display the datetime value in t2;  NOTICE the minutes 
                                                   'changed when 60 was added

t1 = t1 + 0.47        ' another example;  add 47 hundredths of a second to the datetime value in t1
? t1
= 10/19/2005 11:07:[COLOR="#FF0000"]08 00[/COLOR] am                ' and display the result.

Do you understand why [COLOR="#FF0000"]seconds[/COLOR] went from 07 to 08, while hundredths of a second went from 53 to 00?

[G Gabriel]

Re: Adding minutes to a time field

dim start as t
start="01/12/2014 01:53:32 48 pm"
?start+60 '1 minute=60 seconds
= 01/12/2014 01:54:32 48 pm
?start+3600 'adding one hour
= 01/12/2014 02:53:32 48 pm

Same as:

dim start as t
start="01/12/2014 01:53 pm"
?start+60
= 01/12/2014 01:54:00 00 pm
?start+3600
= 01/12/2014 02:53:00 00 pm

[Larry Gordon]

Re: Adding minutes to a time field

Thanks for the advise. I do now understand this specific code, though I was confused for a few hours until I eventually realized there might be a small syntax error in your line 3, Mr G, though I'm still unsure... (with the + and the =).

I then spent 24 hours reading through the xbasic lessons, in conjunction with the above, but regrettably couldn't get the interactive window to stop complaining about my code.

The good news is: after six years of compiling brilliant Alpha applications, it was the first time I'd actually had cause to open the interactive window!

The even better news is, I eventually realized I could very simply achieve my initial goal via the expression builder in my field rules, i.e. Start_time + (Minutes*60)

My error of a few days ago was not realizing that we are calculating in seconds, as you kindly pointed out.

Meanwhile my xbasic problems were largely caused when I tried to replace the date/times - in the examples above - with my field names, especially with quote marks etc. And then I couldn't grasp where to put my code in order to update the relevant field. Like I said over a year ago, I must start learning xbasic... but for now, my application is doing exactly what I wanted. Thanks again.

[G Gabriel]

Re: Adding minutes to a time field

I was confused for a few hours until I eventually realized there might be a small syntax error in your line 3, Mr G, though I'm still unsure.

There was no error.
The line reads:
?start+60 '1 minute=60 seconds
The part in blue, was commented out. Notice the single quote before 1?
I put that there to help you understand where the 60 was coming from.
Evidently this single quote cost you hours of research!