calculating unique time
This WebDNA talk-list message is from 1998
It keeps the original formatting.
numero = 18232
interpreted = N
texte = That is not the problem we originally talked about, therefore the new subject.At 13:01 Uhr 13.06.1998, bob wrote: You set the login time of a user like this: >logintime=[math]{{[time]}+{00:20:00}}+{[date]}[/math] Hmm... I don't think this will be reliable under any circumstances: [math]{date}[/math] returns the number of days since 00/00/000. [math]{time}[/math] returns the seconds since midnight. If you just add the two values, the result will merely depend on the seconds since midnight: Assume we have 729918 days and 64255 seconds now, we get 729918 days + 64255 seconds = 794173 Tomorrow we have 729919 days and let's say 20000 seconds: 729919 days + 20000 seconds = 749919 Effect: the time of tomorrow is older than the value of today! In fact any hit tomorrow which occures before the corresponding today's time will be lower - that is important if the user works around midnight...And here a never-can-be-example ;-) a user logs in today: 729918 days + 64255 seconds = 794173 and tomorrow, one second before he did today: 729919 days + 64254 seconds = 794173 Effect: the two results are identical, but there is actually one day difference! Since WebCat has no (short) function to calculate seconds since the date 00/00/0000, I do some sort of digit-shift to get reliable values:> currenthit=[math]{[date]}[/math]*100000 > +[math]{[time]}[/math][/math] (In clear text: days * 100000 + seconds)For example, a login today: 729918 * 100000 = 72991800000 + 64255 = 729918064255 and a login tomorrow, same time: 729919 * 100000 = 72991900000 + 64255 = 729919064255 Effect: tomorrows value is always higher than today's. Peter__________________________________________ Peter Ostry - po@ostry.com - www.ostry.com Ostry & Partner - Ostry Internet Solutions Auhofstrasse 29 A-1130 Vienna Austria fon ++43-1-8777454 fax ++43-1-8777454-21
Associated Messages, from the most recent to the oldest:
That is not the problem we originally talked about, therefore the new subject.At 13:01 Uhr 13.06.1998, bob wrote: You set the login time of a user like this: >logintime=
[math]{{
[time]}+{00:20:00}}+{
[date]}[/math] Hmm... I don't think this will be reliable under any circumstances:
[math]{date}[/math] returns the number of days since 00/00/000.
[math]{time}[/math] returns the seconds since midnight. If you just add the two values, the result will merely depend on the seconds since midnight: Assume we have 729918 days and 64255 seconds now, we get 729918 days + 64255 seconds = 794173 Tomorrow we have 729919 days and let's say 20000 seconds: 729919 days + 20000 seconds = 749919 Effect: the time of tomorrow is older than the value of today! In fact any hit tomorrow which occures before the corresponding today's time will be lower - that is important if the user works around midnight...And here a never-can-be-example ;-) a user logs in today: 729918 days + 64255 seconds = 794173 and tomorrow, one second before he did today: 729919 days + 64254 seconds = 794173 Effect: the two results are identical, but there is actually one day difference! Since WebCat has no (short) function to calculate seconds since the date 00/00/0000, I do some sort of digit-shift to get reliable values:> currenthit=
[math]{
[date]}[/math]*100000 > +
[math]{
[time]}[/math][/math] (In clear text: days * 100000 + seconds)For example, a login today: 729918 * 100000 = 72991800000 + 64255 = 729918064255 and a login tomorrow, same time: 729919 * 100000 = 72991900000 + 64255 = 729919064255 Effect: tomorrows value is always higher than today's. Peter__________________________________________ Peter Ostry - po@ostry.com - www.ostry.com Ostry & Partner - Ostry Internet Solutions Auhofstrasse 29 A-1130 Vienna Austria fon ++43-1-8777454 fax ++43-1-8777454-21
Peter Ostry
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