A.14 Time and date

XLOGO has several primitives for date, time or generating countdown.



wait n



Halts the program, and therefore the turtle, for 6n0 seconds.



countdown n



Starts a countdown of n seconds. We know if this countdown has finished with the primitive endcountdown?



endcountdown?



Returns "true if there’s no active countdown. Returns "false if the countdown is active.



date



Returns a list wich contains three integers representing the date. The first integer indicates the day, the second the month and the last the year. —> [day month year]



time



Returns a list of three integers representing the time. The first integer indicates the hour, the second the minutes and the last the seconds. —> [hour minute seconde]



pasttime



Returns the past time in seconds since XLOGOhas started.



Difference between wait and countdown is that countdown doesn’t halt the program.



Here is an example: 
 to clock
 # shows time in numerical format
 # we refresh the time each five seconds
 if endcountdown? [
 cs
 sfont 75 ht
 make "heu time
 make "h first :heu
 make "m item 2 :heu
 # We shows two number for seconds and minutes. (we must add a 0)
 if :m-10<0 [make "m word 0 :m]
 make "s last :heu
                                                                                                  
                                                                                                  
 # We shows two number for seconds and minutes. (we must add a 0)
 if :s-10<0 [make "s word 0 :s]
 label word word word word :h ": :m ": :s
 countdown 5
 ]
 clock
 end