Imports System
Module Jan1WeekdayProgram
'
' This program determines the day of the week for January 1st of a given year.
'
' Approach:
' ---------
' VB.NET provides built‑in date/time handling through the Date structure:
' - New Date(year, month, day) : constructs a calendar date
' - Date.DayOfWeek : returns a DayOfWeek enum value
'
' DayOfWeek values:
' Sunday, Monday, Tuesday, Wednesday,
' Thursday, Friday, Saturday
'
' This avoids manual calendar arithmetic and uses efficient built‑in routines.
'
' Convert DayOfWeek enum to a readable string
Function WeekdayName(dow As DayOfWeek) As String
' Convert enum name to "Title Case"
Dim s As String = dow.ToString()
Return Char.ToUpper(s(0)) & s.Substring(1).ToLower()
End Function
' Compute weekday of January 1st for a given year
Function Jan1Weekday(year As Integer) As String
Dim dateValue As New Date(year, 1, 1) ' January 1st of given year
Dim dow As DayOfWeek = dateValue.DayOfWeek
Return WeekdayName(dow)
End Function
Sub Main()
Dim year As Integer = 2026
Dim resultStr As String = Jan1Weekday(year)
Console.WriteLine("January 1st, " & year & " falls on a " & resultStr & ".")
End Sub
End Module
' run:
'
' January 1st, 2026 falls on a Thursday.
'
