filter_gettext.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file

function ee_custom_sold_out_messaging( $translated, $original, $domain ) {
 
    // This is an array of original strings
    // and what they should be replaced with
     $strings = array(
        'Sold&nbsp;Out' => 'Class full',
        'Confirm and go to payment page' => 'Complete registration',
        'No events available...' => 'No upcoming classes at this time...',
	'Event Date Ticket Uses' => 'Class Admission',
	'Sale Dates' => 'Registration Dates',
	'The dates when this option is available for purchase.' => 'Dates when registration is available.',
	'Goes On Sale:' => 'Start',
	'Sales End:' => 'Ends',
	'The number of separate event datetimes (see table below) that this ticket can be used to gain admittance to' => 'Date and time this class is scheduled for',
        // Add some more strings here
    );
 
    // See if the current string is in the $strings array
    // If so, replace its translation
    if ( isset( $strings[$original] ) ) {
        // This accomplishes the same thing as __()
        // but without running it through the filter again
        $translations = get_translations_for_domain( $domain );
        $translated = $translations->translate( $strings[$original] );
    }
 
    return $translated;
}
 
add_filter( 'gettext', 'ee_custom_sold_out_messaging', 10, 3 );

?>

'The number of separate event datetimes (see table below) that this ticket can be used to gain admittance to' => 'Date and time this class is scheduled for',

Should be:

'The number of separate event datetimes (see table below) that this ticket can be used to gain admittance to.%1$s%2$sAdmission is always one person per ticket.%3$s' => 'Date and time this class is scheduled for %1$s%2$sAdmission is always one person per ticket.%3$s'

See: https://eventespresso.com/topic/show-number-of-attendees-for-an-event/#post-240746