JSFiddle - React, Tailwind, and code Playground

HTML

<div id="divtargetDay_1__Assigned" class=" divday divfloatpointerleft"></div>
    <div id="divtargetDay_2__Assigned" class=" divday divfloatpointerleft"></div>
    <div id="divtargetDay_3__Assigned" class=" divday divfloatpointerleft"></div>
    <div id="divtargetDay_4__Assigned" class=" divday divfloatpointerleft"></div>
    <div id="divtargetDay_5__Assigned" class=" divday divfloatpointerleft"></div>
    <div id="divtargetDay_6__Assigned" class=" divday divfloatpointerleft"></div>

CSS

.divday{
    background: silver;

}

.divday:hover  {
   border:1px solid red;
}

.divfloatpointerleft {
    cursor:pointer;
    float:left;
}

.divday {
    width: 56px !important;    
    height: 56px !important; 
    margin-right:4px;   
}