CODEWITHSUNDEEP
javadatetime
Andro Selva
Andro Selva

Reputation: 54332

How to add an hour to my time

I have my time in the below format, and I use this value to set the text of my button.

String strDateFormat = "HH:mm: a";
SimpleDateFormat sdf ;
 sdf = new SimpleDateFormat(strDateFormat);
startTime_time_button.setText(sdf.format(date));

Now my question is, is it possible to add one hour to this time format?

Upvotes: 3

Views: 23141

Answers (5)

Kasim Rangwala - OpenXcell
Kasim Rangwala - OpenXcell

Reputation: 11

If you're confused what to use between Calendar.HOUR & Calendar.HOUR_OF_DAY. go with Calendar.MILLISECOND

val nextHour: Date = Calendar.getInstance().also {
        it.time = Date() // set your date time here
    }.also {
        it.add(Calendar.MILLISECOND, 1 * 60 * 60 * 1000) // 1 Hour
    }.time

Upvotes: 0

user670804
user670804

Reputation:

You have to use Calendar:

Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.HOUR_OF_DAY, 1);
date = cal.getTime();

Upvotes: 11

Jigar Joshi
Jigar Joshi

Reputation: 240996

Calendar cal = Calendar.getInstance();
cal.setTime(setYourTimeHereInDateObj);
cal.add(Calendar.HOUR, 1);
Date timeAfterAnHour = cal.getTime();
//now format this time

See

Upvotes: 5

Paweł Dyda
Paweł Dyda

Reputation: 18662

If you can't use Jabal's suggestion (i.e. you are not allowed to use non-JDK libraries), you can use this:

long hour = 3600 * 1000; // 3600 seconds times 1000 milliseconds
Date anotherDate = new Date(date.getTime() + hour);

If by a chance you are looking for time zone conversion, you can simply assign one to your formatter, it would work faster:

TimeZone timeZone = TimeZone.getTimeZone("UTC"); // put your time zone instead of UTC
sdf.setTimeZone(timeZone);

BTW. Hard-coding date format is not the best of ideas. Unless you have a good reason not to, you should use the one that is valid for end user's Locale (DateFormat df = DateFormat.getTimeInstance(DateFormat.DEFAULT, locale);). Otherwise you create i18n defect (who cares, I know).

Upvotes: 2

jabal
jabal

Reputation: 12367

I think the best and easiest way is using Apache Commons Lang:

Date incrementedDate = DateUtils.addHour(startDate, 1);

http://commons.apache.org/lang/api-2.6/org/apache/commons/lang/time/DateUtils.html

Upvotes: 6

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