Task: Calendar
C#: using System;
using System.Collections.Generic; 
using System.Linq;
using System.Text;

namespace CalendarStuff
{
 
    class Program
    {
        static void Main(string[] args)
        {
            Console.WindowHeight = 46;
            Console.Write(buildMonths(new DateTime(1969, 1, 1)));
            Console.Read(); 
        }
        private static string buildMonths(DateTime date)
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendLine(center("[Snoop]", 24 * 3));
            sb.AppendLine();
            sb.AppendLine(center(date.Year.ToString(), 24 * 3));

            List<DateTime> dts = new List<DateTime>();
            while (true)
            {
                dts.Add(date);
                if (date.Year != ((date = date.AddMonths(1)).Year))
                {
                    break;
                }
            }
            var jd = dts.Select(a => buildMonth(a).GetEnumerator()).ToArray();
            
            int sCur=0;
            while (sCur<dts.Count)
            {
                sb.AppendLine();
                int curMonth=0; 
                var j = jd.Where(a => curMonth++ >= sCur && curMonth - 1 < sCur + 3).ToArray(); 
                sCur += j.Length; 
                bool breakOut = false;
                while (!breakOut)
                {
                    int inj = 1;
                    foreach (var cd in j)
                    {
                        if (cd.MoveNext())
                        {
                            sb.Append((cd.Current.Length == 21 ? cd.Current : cd.Current.PadRight(21, ' ')) + "     ");
                        }
                        else
                        {
                            sb.Append("".PadRight(21, ' ') + "     ");
                            breakOut = true;
                        }
                        if (inj++ % 3 == 0) sb.AppendLine();
                    }
                }

            }
            return sb.ToString();
        }


        private static IEnumerable<string> buildMonth(DateTime date)
        {
            yield return center(date.ToString("MMMM"),7*3);
            var j = DateTime.DaysInMonth(date.Year, date.Month);
            yield return Enum.GetNames(typeof(DayOfWeek)).Aggregate("", (current, result) => current + (result.Substring(0, 2).ToUpper() + " "));
            string cur = "";
            int total = 0;

            foreach (var day in Enumerable.Range(-((int)date.DayOfWeek),j + (int)date.DayOfWeek))
            {
                cur += (day < 0 ? "  " : ((day < 9 ? " " : "") + (day + 1))) +" ";
                if (total++ > 0 && (total ) % 7 == 0)
                {
                    yield return cur;
                    cur = "";
                }
            }
            yield return cur;
        }
        private static string center(string s, int len)
        {
            return (s.PadLeft((len - s.Length) / 2 + s.Length, ' ').PadRight((len), ' '));
        } 
    }
}

Go: package main

import (
	"fmt"
	"time"
)

const pageWidth = 80

func main() {
	printCal(1969)
}

func printCal(year int) {
	thisDate := time.Date(year, 1, 1, 1, 1, 1, 1, time.UTC)
	var (
		dayArr                  [12][7][6]int 
		month, lastMonth        time.Month
		weekInMonth, dayInMonth int
	)
	for thisDate.Year() == year {
		if month = thisDate.Month(); month != lastMonth {
			weekInMonth = 0
			dayInMonth = 1
		}
		weekday := thisDate.Weekday()
		if weekday == 0 && dayInMonth > 1 {
			weekInMonth++
		}
		dayArr[int(month)-1][weekday][weekInMonth] = thisDate.Day()
		lastMonth = month
		dayInMonth++
		thisDate = thisDate.Add(time.Hour * 24)
	}
	centre := fmt.Sprintf("%d", pageWidth/2)
	fmt.Printf("%"+centre+"s\n\n", "[SNOOPY]")
	centre = fmt.Sprintf("%d", pageWidth/2-2)
	fmt.Printf("%"+centre+"d\n\n", year)
	months := [12]string{
		" January ", " February", "  March  ", "  April  ",
		"   May   ", "   June  ", "   July  ", "  August ",
		"September", " October ", " November", " December"}
	days := [7]string{"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"}
	for qtr := 0; qtr < 4; qtr++ {
		for monthInQtr := 0; monthInQtr < 3; monthInQtr++ { 
			fmt.Printf("      %s           ", months[qtr*3+monthInQtr])
		}
		fmt.Println()
		for monthInQtr := 0; monthInQtr < 3; monthInQtr++ { 
			for day := 0; day < 7; day++ {
				fmt.Printf(" %s", days[day])
			}
			fmt.Printf("     ")
		}
		fmt.Println()
		for weekInMonth = 0; weekInMonth < 6; weekInMonth++ {
			for monthInQtr := 0; monthInQtr < 3; monthInQtr++ {
				for day := 0; day < 7; day++ {
					if dayArr[qtr*3+monthInQtr][day][weekInMonth] == 0 {
						fmt.Printf("   ")
					} else {
						fmt.Printf("%3d", dayArr[qtr*3+monthInQtr][day][weekInMonth])
					}
				}
				fmt.Printf("     ")
			}
			fmt.Println()
		}
		fmt.Println()
	}
}