MIPS example: day of week

This program reads a valid date (3 integers being date (d), month (m), year
using the Zeller's algorithm described below:

---

          .data
day:      .asciiz "Please enter the date: "
dayA:     .word day
month:    .asciiz "Please enter the month: "
monthA:   .word month
year:     .asciiz "Please enter the year: "
yearA:    .word year
          .text
main:     #-------------------------------------------------------
          # Write a program that reads a valid date (3 integers being date (d), month (m), year
          # the week (Sun, Mon, Tue, etc.) using the Zeller's algorithm described below:
          #
          # if (m <= 2){
          #     m = m + 12;
          #     y = y - 1;
          # }
          # tmp1 = (26 * (m + 1)) / 10;
          # tmp2 = (125 * y) / 100;
          # tmp3 = d + tmp1 + tmp2 – (y / 100) + (y / 400) - 1;
          # dow = tmp3 % 7;
          #
          # The resulting integer in dow (day-of-week) denotes the day. If dow equals 0, then the day is Sunday. If dow
          # equals 1 then the day is Monday, and so on for the rest of the days in a week. Your program should output the
          # day in words depending on the value of dow.
          #-------------------------------------------------------
          lw   $a0, dayA($0)
          addi $v0, $0, 4
          syscall
         
          addi $v0, $0, 5
          syscall
          add  $s0, $0, $v0
         
          lw   $a0, monthA($0)
          addi $v0, $0, 4
          syscall
         
          addi $v0, $0, 5
          syscall
          add  $s1, $0, $v0
         
          lw   $a0, yearA($0)
          addi $v0, $0, 4
          syscall
         
          addi $v0, $0, 5
          syscall
          add  $s2, $0, $v0
         
          #----------------------
          addi $t4, $0, 2
          sgt  $t0, $s1, $t4
          bne  $t0, $0, skip
          addi $s1, $s1, 12
          addi $t4, $0, 1
          sub  $s2, $s2, $t4
         
skip:     addi $s1, $s1, 1
          sll  $t0, $s1, 4
          add  $t1, $0, $t0
          sll  $t0, $s1, 1
          add  $t1, $t1, $t0
          sll  $t0, $s1, 3
          add  $t1, $t1, $t0
         
          addi $t0, $0, 10
          div  $t1, $t0
          mflo $a0
          add  $t1, $0, $a0
      

          sll  $t0, $s2, 6
          add  $t2, $0, $t0
          sll  $t0, $s2, 5
          add  $t2, $t2, $t0
          sll  $t0, $s2, 4
          add  $t2, $t2, $t0
          sll  $t0, $s2, 3
          add  $t2, $t2, $t0
          sll  $t0, $s2, 2
          add  $t2, $t2, $t0
          add  $t2, $t2, $s2
         
          addi $t0, $0, 100
          div  $t2, $t0
          mflo $a0
          add  $t2, $0, $a0
         
           
          add  $t3, $s0, $t1
          add  $t3, $t3, $t2
          addi $t0, $0, 100
          div  $s2, $t0
          mflo $a0
          sub  $t3, $t3, $a0
          addi $t0, $0, 400
          div  $s2, $t0
          mflo $a0
          add  $t3, $t3, $a0
          addi $t4, $0, 1
          sub  $t3, $t3, $t4
         
          addi $t0, $0, 7
          div  $t3, $t0
          mfhi $a0
          add  $t2, $0, $a0
         
          addi $v0, $0, 1
          syscall
         
          #-----------------------
          jr   $ra