use chrono::{Datelike, NaiveDate};
fn print_year(year: i32) {
for month in 1..=12 {
print_month(year, month);
println!();
}
}
fn print_month(year: i32, month: u32) {
let first = NaiveDate::from_ymd_opt(year, month, 1).unwrap();
let month_name = first.format("%B").to_string();
println!();
println!("{:>15} {}", month_name, year);
println!("Su Mo Tu We Th Fr Sa");
// Sunday = 0, Monday = 1, ...
let indent = first.weekday().num_days_from_sunday();
for _ in 0..indent {
print!(" ");
}
// Days in month: go to next month, day 0
let next_month = if month == 12 { 1 } else { month + 1 };
let next_year = if month == 12 { year + 1 } else { year };
let days_in_month =
NaiveDate::from_ymd_opt(next_year, next_month, 1).unwrap()
.pred_opt().unwrap()
.day();
for day in 1..=days_in_month {
print!("{:2} ", day);
if (indent + day) % 7 == 0 {
println!();
}
}
println!();
}
fn main() {
print_year(2026);
}
/*
run:
January 2026
Su Mo Tu We Th Fr Sa
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
February 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
March 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31
April 2026
Su Mo Tu We Th Fr Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30
May 2026
Su Mo Tu We Th Fr Sa
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
June 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30
July 2026
Su Mo Tu We Th Fr Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
August 2026
Su Mo Tu We Th Fr Sa
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31
September 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30
October 2026
Su Mo Tu We Th Fr Sa
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
November 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30
December 2026
Su Mo Tu We Th Fr Sa
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31
*/
