Rust program to get the current weekday number from Monday

Rust | Date & Time Example: Write a program to get the current weekday number from Monday.
Submitted by Nidhi, on November 08, 2021

Problem Solution:

In this program, we will get the current date-time using Utc::now() method, and then we will get the current weekday number from Monday.

Add Chrono date-time external library to your project

Create your project using the below command.
```
$cargo new datetime -bin
```
Goto the project folder cd datetime and edit Cargo.toml file.
```
$datetime>nano Cargo.toml
```
Then add dependency in Cargo.toml file
```
[dependencies]
chrono = "0.4"
```
After that, build your project using the below command
```
$datetime>cargo build
```
Then execute your project after modification in src/main.rs source file.
```
$datetime>cargo run
```

Program/Source Code:

The source code to get the current weekday number from Monday is given below. The given program is compiled and executed on UBUNTU 18.04 successfully.

// Rust program to get the number of 
// current weekday from Monday

use chrono::prelude::*;

fn main() {
    let dt = Utc::now();
    println!("Weekday number from Monday is : {}", dt.weekday().number_from_monday());
}

Output:

$datetime> cargo run
   Compiling datetime v0.1.0 (/home/arvind/Desktop/rust/datetime)
    Finished dev [unoptimized + debuginfo] target(s) in 0.29s
     Running `target/debug/datetime`

Weekday number from Monday is : 6

Explanation:

In the above program, we imported the "Chrono" library to our project for performing date and time operations. We imported the Chrono library using the below line:

use chrono::prelude::*;

In the main() function, we got the current date and time using Utc::now() method. Then we got the current weekday number from Monday using the number_from_monday() function and printed the result.