calendar.gms : Calendar Function Examples
Calendar Function Examples
Reference:
- GAMS Development Corporation, Formulation and Language Example.
Small Model of Type: GAMS
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$title Calendar Function Examples (CALENDAR,SEQ=183)
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Calendar Function Examples
GAMS Development Corporation, Formulation and Language Example.
The Date and Time Functions are:
Serial = Jstart (start of Gams Job)
Serial = JNow (current date/time stamp)
Year = GYear (serial)
Month = GMonth (serial)
Day = GDay (serial)
Hours = GHour (serial)
Minute = GMinute(serial)
Second = GSecond(serial)
DoW = GDoW (serial) (1=Monday,2=Tuesday,..)
Leap = GLeap (serial) (0=no leap year, 1=leap year)
DSerial = JDate(Year,Month,Day) (full days)
TSerial = JTime(Hour,Minute,Second); (fraction of day)
Inputs to the J(ulian) Functions are Gregorian dates and the
G(regorian) Functions are days since January 1, 1900.
The Jstart/Jnow return a serial number that measures the time
elapsed since January 1, 1900, at 00:00:00 in days.
Note the relationship below:
jstart == jdate(gyear(jstart),gmonth (jstart),gday (jstart))
+ Jtime(ghour(jstart),gminute(jstart),gsecond(jstart))
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scalar start date + time at start of GAMS job
now current date + time
year, month, day, hour, minute, second, dow, leap
date, time, diff, sdate, stime, diff;
start = jstart; now=jnow;
year = gyear(start); month = gmonth (start); day = gday (start);
hour = ghour(start); minute = gminute(start); second = gsecond(start);
dow = gdow (start);
leap = gleap(start);
display start,now, year, month, day, hour, minute, second, dow, leap;
date = jdate(year,month,day);
time = jtime(hour,minute,second);
diff = start - (date+time);
sdate = floor(start);
stime = mod(start,1);
display date,time,diff,sdate,stime;
{ get resolution of jnow by looking at the first 5 changes }
scalar test, i, old, new, sec;
new=jnow;
for(i=1 to 5,
old = new;
while(old=new, ?? burn time until Jnow changes
new=jnow;);
test = new - old; display test;
sec = gsecond(new)-gsecond(old);
display sec );
{ now we want to know when to celebrate the year 2000 }
scalar s2000,days2000,hours2000,min2000,sec2000;
s2000 = jdate(2000,1,1)-jnow;
days2000 = floor(s2000);
hours2000 = floor(mod(s2000,1)*24);
min2000 = floor(mod(s2000*24,1)*60);
sec2000 = mod(s2000*24*60,1)*60;
display 'all truncated numbers',days2000,hours2000,min2000,sec2000;
days2000 = s2000;
hours2000 = mod(days2000,1)*24;
min2000 = mod(hours2000,1)*60;
sec2000 = mod(min2000,1)*60;
display 'all fractional numbers',days2000,hours2000,min2000,sec2000;
{ print a calendar for a number of years }
set w / Mon, Tue, Wed, Thu, Fri, Sat, Sun /
m / January, February, March, April, May, June, July, August, September, October, November, December /
y / 1997,1998,1999,2000/
parameter dim(y,m) days in month
ym(y) year
sm(m) next month;
sm(m--1) = ord(m);
ym(y) = ord(y)+1996;
dim(y,m) = jdate(ym(y)+(card(m)=ord(m)),sm(m),1)-jdate(ym(y),ord(m),1)
display sm,dim;
file calendar; put calendar @12 'C a l e n d a r' /
@12 '---------------' /;
loop(y,
put // @13 'Year = ' y.tl
loop(m,
put // @15 ,m.tl /;
loop(w, put w.tl:>5);old=1;
for(i=1 to dim(y,m),
date = jdate(ym(y),ord(m),i);
put$old / ;
put @((gdow(date)-1)*5+1) i:5:0;
old = calendar.cc >= card(w)*5 ) ) );
{ print a calendar from today for 400 days }
file calendar; put //// @12 'C a l e n d a r' /
@12 '---------------' /;
month = 0;
for(i=jstart to jstart+400,
if(month<>gmonth(i),
month = gmonth(i);
put // @15 ,month:2:0 '/' gyear(i):4:0 /;
loop(w, put w.tl:>5); put / );
put$(calendar.cc >= card(w)*5) /;
put @((gdow(i)-1)*5+1) gday(i):5:0 );
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