Small Assembly 8051 program

Hello there! I need someone to help me implement a small program in Assembly. Here is the description: A stopwatch (minutes and seconds) is installed on a track for skying. The skier causes a start of time tracking on the stopwatch as soon as he starts skying and stops the timing at the finish. The following skier clears the previous result on the timer with his start and starts his time display. Write a handler for this system using timer 1 running without interrupts. Basically, I need to implement an Assembly program that works like an infinite stopwatch with minutes and seconds on it. The example with skiers is just for a better understanding of the task. There are no actual skiers involved in the program. :D It can work like, for example, we have a physical button and a table. When a user clicks on the button, the time begins to track on this table. When a user clicks on it once again, the time on the table resets, and the time tracking begins from start (from 00:00)