4 Lines Javascript Solution
\nJavaScript 0(1) Solution\n\n\n\n\n\nvar numberOfRounds = function(startTime, finishTime) {\n    var start=60*parseInt(startTime.slice(0,2))+parseInt(startTime
\n**JavaScript 0(1) Solution**\n\n\n![image](https://assets.leetcode.com/users/images/64b3fd37-bc2b-43cc-a0bf-b63ee7f31876_1624162827.384518.png)\n\n```\nvar numberOfRounds = function(startTime, finishTime) {\n    var start=60*parseInt(startTime.slice(0,2))+parseInt(startTime.slice(3))\n    var end=60*parseInt(finishTime.slice(0,2))+parseInt(finishTime.slice(3))\n    if(start>end) end+=24*60\n    return Math.floor(end/15) - Math.ceil(start/15)\n};\n```
['Math', 'JavaScript']