[Newby] About Date

[buzzqw]

maybe a very stupid question but i not found a intelligent solution...

how to calculate the time elapsed between two date

I MEAN :

first date 01/03/2004
second date 24/01/2006

time elapsed=1 year , 10 month, 23 days (i hope my calculation is correct...)

THANKS !

BHH

[flaith]

With this code you'll have the number of days between dates ->

Code: Select all

; --------------------
; Procédures calcul de date
; Auteur : Paneric
; Date : 22/09/2004
;
;- Procédures
;
Procedure.l NombredeJoursduMois(mois.l, annee.l)
  longueurdumois.l = 0
  If mois = 4 Or mois = 8 Or mois = 9 Or mois = 11
    longueurdumois = 30
  Else
    If mois = 2
      If annee % 4 = 0
        If annee%100 = 0 And annee%400 <> 0
          longueurdumois = 28
        Else
          longueurdumois = 29
        EndIf
      Else
        longueurdumois = 28
      EndIf
    Else
      longueurdumois = 31
    EndIf
  EndIf
  ProcedureReturn longueurdumois
EndProcedure

Procedure.l NombredeJoursentreDate(jour1.l, mois1.l, annee1.l, jour2.l, mois2.l, annee2.l)
  Intervalle.l = 0
  m.l = 0
  If annee1 + 1 <= annee2 - 1
    For j.l = annee1.l To annee2.l
      longueurdumois.l = NombredeJoursduMois(2, j)
      If longueurdumois = 28
        Intervalle + 365
      Else
        Intervalle + 366
      EndIf
    Next j
  EndIf
  If annee1 < annee2
    send.l = 12
  Else
    send = mois2 - 1
  EndIf
  If mois1 < send
    For m = mois1 + 1 To send
      Intervalle + NombredeJoursduMois(m, annne1)
    Next m
  EndIf
  If mois2 > 1 And send = 12
    For m = 1 To mois2 - 1
      Intervalle + NombredeJoursduMois(m, annne2)
    Next m
  EndIf
  If (mois1 = mois2) And (annee1 = annee2)
    Intervalle = jour2 - jour1
  Else
    Intervalle + (NombredeJoursduMois(mois1, annee1) - jour1)
    Intervalle + jour2
  EndIf
  ProcedureReturn Intervalle
EndProcedure

;today
y.l = Year(Date())
m.l = Month(Date())
d.l = Day(Date())

debug NombredeJoursentreDate(01, 03, 2004,d, m, y)

[Behnood]

just look at the date command of date library in General Libraries section of purebasic manual.
it's completely covers what you need

[buzzqw]

thanks ! i will look harder...

BHH

[Behnood]

for finding days between 2 dates you can just use this:

date1=ParseDate("%yyyy/%mm/%dd", "2004/03/01")
date2=ParseDate("%yyyy/%mm/%dd", "2006/01/24")
date_bet=date2-date1

it will return seconds between date easily. so calculating days will be no matter then.

if you need precise answer (i mean counting intercalary years, different in month's days) you have to calculate it (may be there is a lib for that, i don't know) but if it isn't matter to have the precise answer, you can just use date() and it will return the date for seconds past from 1st jan 1970, so you know what you must do.

by the way it's 694 days between your dates and so it will be 1year 11months and 24days

[Dare2]

Is it possible there is a base year you can subtract after converting to seconds, taking one from the other, and reconverting?

If not, the calc in basic code is pretty long winded requiring you work out leap years, false leap years, false false leap years and etc.

[Jan Vooijs]

And to make it even easier:

Code: Select all

date1=ParseDate("%yyyy/%mm/%dd", "2004/03/01")
date2=ParseDate("%yyyy/%mm/%dd", "2006/01/24")
date_bet=date2-date1

Debug date_bet


Text.s = FormatDate( "%yyyy/%mm/%dd", Date_bet)

Debug Text.s

Gives as answer 1971/11/26 or 1 yr 11 months and 26 days...

[Dare2]

hehe.

So 1970 is the base year!

Thanks.

[Behnood]

as i know every software has its own base for date calculation. some take 1900 as a base (like ms products)
it's up to programmer and what he needs actually. cause dealing with date can be so hard. for example how i can find which day of week was 5000bc?!;-) there will be 2 answers, exact one and possible one. finding the exact one means you have to deal with calendar calculation in deep. but for a good approach i think counting seconds from the base is enough.

[Behnood]

in my post, didn't i mention that the seconds will be count from 1st jan 1970?
wish to be helpful

[Dare2]

lol. You did too! I missed it.

[Jan Vooijs]

Dare2,

As memory serves I believe the 1970 calculations are a build-IN feature of MS windows since version 1.0 and YES they are exact to the second! Even leapyears and leap centuries are done correctly!! tested them myself...

There are even julian calculus in MS Windows (yes from 1/1/1900 til i believe the year 2800 (or 3500) i am not shure about the top date.

So fred has (had?) nothing to do with it just a call to windows and back to us the users...

Jan V.

[Dare2]

Hi Jan,

That's interesting. Makes a change from DOS days when you had to roll your own!

[buzzqw]

there is something wrong...

Code: Select all

date1=ParseDate("%yyyy/%mm/%dd", "2004/03/01")
date2=ParseDate("%yyyy/%mm/%dd", "2006/01/24")
date3=ParseDate("%yyyy/%mm/%dd", "1970/01/01")
date_bet=date2-date1-date3  ;<<<<< please note this

Debug date_bet

Text.s = FormatDate( "%yyyy/%mm/%dd", Date_bet)

Debug Text.s 

in this way i would 01/11/26 BUT no i always get 1971 !



BHH

[Jan Vooijs]

dare2,

Well good old Turbo Pascal had the Julian date functions for a very long time (That was under MS DOS)

Cheers

Jan V.
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