Single Array into multiple Array list

can someone tel me how to achieve this...

entry=["start":"07:00 pm","end":"07:45 pm","rule":
"**MO,WE**","summary":"test1"]

***into***

array=[
{"start":"07:00 pm","end":"07:45 pm","rule":"MO,WE","summary":"test1","day":"**WE**"},
{"start":"07:00 pm","end":"07:45 pm","rule":"MO,WE","summary":"test1","day":"WE"(instead it should be '**MO**'}]    

here is the code i tried for getting entry.day... but it didn't work...
   var temprule=entry.rule;//"MO,WE"
    var rulest =[];
    rulest=temprule.split(',');
    for(var j = 0; j < rulest.length; j++) {        
        var obj1 = Object.assign(rulest[j]);
             entry.day=obj1;  //getting only WE each time when the array passes
                     jsondata.push(entry); // it has all elements like start,end,summary,rule and we need to add day to this...
       }  

I am not sure why it keeps adding same value in day thou its looped:( is that achievable thru code ? .. Thanks

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