title: How to construct ZonedDateTime from an Instant and a time string?
body: <p>Given an object of <code>Instant</code>, a <code>time string</code> representing the time at a specific <code>ZoneId</code>, How to construct a <code>ZonedDateTime</code> object with the date part (year, month, day) from the instant at the given <code>ZoneId</code> and the time part from the given <code>time string</code>?</p>
  
  <p>For example:</p>
  
  <p>Given an object of Instant of value <strong>1437404400000</strong> (equivalent to <strong>20-07-2015 15:00 UTC</strong>), a time string <strong>21:00</strong>, and an object of <code>ZoneId</code> representing <strong>Europe/London</strong>, I want to construct an object of <code>ZonedDateTime</code> equivalent to <strong>20-07-2015 21:00 Europe/London</strong>.</p>