Question: Very primitive question.

```
String startTime = "2020-07-15T17:35:00Z";

```

I want to add 3.5 hours to this string. Timezone is UTC. How should i do that ?

I tried going through TemporalAccessor and DateTimeFormatter but no success.

```
DateTimeFormatter formatter = DateTimeFormatter.ISO_INSTANT;
TemporalAccessor temporalAccessor = formatter.parse(startTime);
final LocalDateTime parse = LocalDateTime.parse(startTime, formatter);

```

Answer: 
```
String startTimeString = "2020-07-15T17:35:00Z";
final LocalDateTime startTime = LocalDateTime.parse(startTimeString, DateTimeFormatter.ISO_DATE_TIME);
LocalDateTime endTime = startTime.plusHours(3).plusMinutes(30);
String endTimeString = endTime.format(DateTimeFormatter.ISO_DATE_TIME);

```
You can parse from string to `Instant` and then add 3.5 hour. Then again format into the string.

```
String startTime = "2020-07-15T17:35:00Z";
DateTimeFormatter formatter = DateTimeFormatter.ISO_INSTANT;
Instant instant = Instant.from(formatter.parse(startTime));
instant = instant.plusSeconds((3*60*60)+(30*60));
startTime = formatter.format(instant);

```

Output:

```
2020-07-15T21:05:00Z

```