date.html

<script>
    (function(){
        const now = new Date()
        let offset = now.getTimezoneOffset()
        let dst = 60
        if( ( now.getMonth() < 3)&&( now.getDate() < 10)){ dst = 0
        }
        if( ( now.getMonth() > 9 ) && ( now.getDate() < 2 ) ){ dst = 0}
        switch(offset)
        {
            case (300 - dst ) : offset = 'EastCost' ; break
            case (360 - dst) : offset = 'Central' ; break
            case(420 - dst ) : offset = 'Mountain' ; break
            case (480 - dst ) : offset = 'Pacific' ; break
            default : offset = 'All'
        }
        console.log('System Time: ' + now.toString())
        console.log('UTC (GMT) Time: ' + now.toUTCString())
        console.log('\nWelcome to ' + offset + 'Visitors' )
   })()
</script>