Extrapolating date and time from dataset Timestamp

Hi all, I’m trying to load records from a dataset that are more recent than a timestamp I had saved previously. Seeing the different timezones and country date/time formats that a dataset may contain and that my PC may return, how can I query a database making sure I can compare similar timestamps? Here’s the code:

lastSentMessage  =  Date (); 

$w ( "#myDataset" ). setFilter (  wixData . filter () 
    . gt ( "_createdDate" ,  lastSentMessage )     //  
) 
	. then ( () => { 
    	**if** ( $w ( "#myDataset" ). getCurrentItem () !=  **null** ) 
        { 
        		console . log ( "HERE: " +  					$w ( "#myDataset" ). getTotalCount ()); 
    	} 
} ) 
    . **catch** ( ( err ) => { 
		console . log ( err ); 
} );