Unix Style Timestamps???

 BBS: Inland Empire Archive
Date: 07-19-92 (19:49)             Number: 31
From: JEAN CREPEAU                 Refer#: NONE
  To: STEVE MATHIESON               Recvd: NO  
Subj: Unix Style Timestamps???       Conf: (2) Quik_Bas

In a message to ALL, STEVE MATHIESON wrote:
SM=> Howdy All!

SM=> Can anyone explain to me  how to deal with Unix style  timestamps? I'm
    writting a program and one of the files it reads contains such a field,
    and  for  the  life  of  me,  I  can't  figure  out how to make it into
    something more readable. It's basically a large number that  represents
    the number of seconds since January 1 1970, and it _should_ be possible
    to get the date  and time out of  this number. But I  don't know how...
    Can anyone help?


deflng a-z

function getcode (yy,mm,dd,h,m,s)
getcode=(getct(yy,mm,dd)-getct(1970,1,1))*86400+s+60*m+3600*h
end function

function getct (y,m,d)
z=y+(m < 3)
x=z*365+z\4-z\100+z\400+d
select case m
case 1:x=x+365
case 2:x=x+396
case 3:x=x+59
case 4:x=x+90
case 5:x=x+120
case 6:x=x+151
case 7:x=x+181
case 8:x=x+212
case 9:x=x+243
case 10:x=x+273
case 11:x=x+304
case 12:x=x+334
end select
getct=x
end function

sub getdatetime (code,yy,mm,dd,h,m,s)
cd=int(code/86400):ct=code-cd*86400
yy=1970:mm=1:dd=cd:cd=cd+getct(1970,1,1)
do
        q=cd-getct(yy,mm,dd)
        dd=dd+q
        select case mm
        case 1,3,5,7,8,10,12:nd=31
        case 2:nd=28-((yy\4)*4=yy)+((yy\100)*100=yy)-((yy\400)*400=yy)
        case else:nd=30
        end select
        nm=int((dd-1)/nd):dd=dd-nm*nd:mm=mm+nm
        ny=int((mm-1)/12):mm=mm-ny*12:yy=yy+ny
        if ny=0 and nm=0 and q=0 then exit do
loop
end sub


To convert a Unix Stamp (Code) to YY-MM-DD, HH:MM:SS:
        GetDateTime Code,YY,MM,DD,H,M,S

To convert time/date to a Unix Stamp
        Code=GetCode(YY,MM,DD,H,M,S)

The other function is used to compute date codes (number of days since  00-
00-0000). You can use it to compute the number of days between to dates  or
to get the day of the week
        DayOfWeek=GetCT(YY,MM,DD) mod 7
        Select case DayOfWeek
        case 0:print "Saturday"
        case 1:print "Sunday"
        case 2:print "Monday"
        case 3:print "Tuesday"
        case 4:print "Wednesday"
        case 5:print "Thursday"
        case 6:print "Friday"
        end select


                Jean
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