> For the complete documentation index, see [llms.txt](https://www.pranaypourkar.co.in/the-programmers-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.pranaypourkar.co.in/the-programmers-guide/java/java-basics/java-data-types/specialized-classes/date-and-time/examples.md). # Examples ## LocalDate ### 1. Extract day of week Given input is year, monthe and day. Find the day of week. ```java public String getDay(int day, int month, int year) { LocalDate localDate = LocalDate.of(year, month, day); return localDate.getDayOfWeek().name(); // Example: WEDNESDAY } ``` ## LocalDateTime ### 1. Given a date and time in string. Attach a timezone to it. ```java LocalDateTime date = LocalDateTime.parse("2023-09-11T11:40"); ``` This `LocalDateTime` **has no timezone information** — it just means *"11:40 on Sept 11th, 2023"*, but not in any particular zone. ```java // System default: UTC ZonedDateTime utcZoned = date.atZone(ZoneId.of("UTC")); // KSA: Asia/Riyadh (UTC+3) ZonedDateTime ksaZoned = date.atZone(ZoneId.of("Asia/Riyadh")); System.out.println("UTC Zoned: " + utcZoned.toInstant()); // UTC Zoned: 2023-09-11T11:40:00Z System.out.println("KSA Zoned: " + ksaZoned.toInstant()); // KSA Zoned: 2023-09-11T08:40:00Z // Convert to Date Date ksaDate = Date.from(ksaZoned.toInstant()); Date utcDate = Date.from(utcZoned.toInstant()); ``` {% hint style="info" %} Notice: **same `LocalDateTime`, different `Instant`** based on the zone. {% endhint %} ## ZonedDateTime ### 1. Get current UTC time in yyyy-MM-dd'T'HH:mm:ss.SSSZ format ```java ZonedDateTime utcNow = ZonedDateTime.now(ZoneOffset.UTC); DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ"); String formatted = utcNow.format(formatter); System.out.println(formatted); // Example: 2025-06-21T07:33:46.115+0000 ``` ### 2. Convert the current time to **Saudi Arabia time**, which is in the `Asia/Riyadh` time zone, and yyyy-MM-dd'T'HH:mm:ss.SSSZ format ```java ZonedDateTime ksaTime = ZonedDateTime.now(ZoneId.of("Asia/Riyadh")); DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ"); String formatted = ksaTime.format(formatter); System.out.println(formatted); // Example: 2025-06-21T10:33:46.123+0300 ``` ### 3. Get a datetime in "dd/MM/yyyy HH:mm" with ZoneId ZONEID\_ASIA\_RIYADH = ZoneId.of("Asia/Riyadh") ```java import java.time.LocalDateTime; import java.time.ZoneId; import java.time.ZonedDateTime; import java.time.format.DateTimeFormatter; public class DateTimeFormattingExample { public static final ZoneId ZONEID_ASIA_RIYADH = ZoneId.of("Asia/Riyadh"); public static void main(String[] args) { // Get the current LocalDateTime LocalDateTime localDateTime = LocalDateTime.now(); // Convert LocalDateTime to ZonedDateTime with the specified ZoneId ZonedDateTime zonedDateTime = localDateTime.atZone(ZONEID_ASIA_RIYADH); // Format ZonedDateTime using a DateTimeFormatter String formattedDateTime = zonedDateTime.format(DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm")); // Print the formatted datetime System.out.println("Formatted DateTime: " + formattedDateTime); } } ``` ## OffsetDateTime ### 1. Convert a given String OffsetDateTime to different Timezone ```java import java.time.OffsetDateTime; import java.time.ZoneId; public class TimeZoneExample { public static void main(String[] args) { // Example OffsetDateTime OffsetDateTime dateTime = OffsetDateTime.parse("2023-05-15T07:08:59.077561Z"); // Convert to a different time zone ZoneId desiredTimeZone = ZoneId.of("America/New_York"); OffsetDateTime convertedDateTime = dateTime.withOffsetSameInstant(desiredTimeZone.getRules().getOffset(dateTime.toInstant())); System.out.println("Original DateTime: " + dateTime); System.out.println("Converted DateTime: " + convertedDateTime); } } ``` ### 2. OffsetDateTime to LocalDate ```java import java.time.OffsetDateTime; import java.time.LocalDate; public class LocalDateExample { public static void main(String[] args) { // Example OffsetDateTime OffsetDateTime dateTime = OffsetDateTime.parse("2023-05-15T07:08:59.077561Z"); // Extract the date component LocalDate localDate = dateTime.toLocalDate(); System.out.println("Original DateTime: " + dateTime); // Original DateTime: 2023-05-15T07:08:59.077561Z System.out.println("Extracted Date: " + localDate); // Extracted Date: 2023-05-15 } } ``` ### 3. OffsetDateTime to ZonedDateTime ```java import java.time.OffsetDateTime; import java.time.ZoneId; import java.time.ZonedDateTime; public class TimeZoneExample { public static void main(String[] args) { // Example OffsetDateTime OffsetDateTime dateTime = OffsetDateTime.parse("2023-05-15T07:08:59.077561Z"); // Convert to the KSA time zone (Arabia Standard Time) ZoneId ksaTimeZone = ZoneId.of("Asia/Riyadh"); ZonedDateTime convertedDateTime = dateTime.atZoneSameInstant(ksaTimeZone); System.out.println("Original DateTime: " + dateTime); System.out.println("Converted DateTime (KSA): " + convertedDateTime); } } ``` ### 4. OffsetDateTime to String ```java import java.time.OffsetDateTime; import java.time.ZoneId; import java.time.ZonedDateTime; import java.time.format.DateTimeFormatter; public class TimeZoneExample { public static final ZoneId ZONEID_ASIA_RIYADH = ZoneId.of("Asia/Riyadh"); public static final String DATE_FORMAT = "yyyy-MM-dd"; public static final String TIME_FORMAT = "HH:mm:ss"; public static void main(String[] args) { // Example OffsetDateTime OffsetDateTime paymentDateTime = OffsetDateTime.parse("2023-05-15T07:08:59.077561Z"); // Convert to the "Asia/Riyadh" time zone and format the date and time components separately String formattedDate = paymentDateTime .atZoneSameInstant(ZONEID_ASIA_RIYADH) .format(DateTimeFormatter.ofPattern(DATE_FORMAT)); String formattedTime = paymentDateTime .atZoneSameInstant(ZONEID_ASIA_RIYADH) .format(DateTimeFormatter.ofPattern(TIME_FORMAT)); System.out.println("Original DateTime: " + paymentDateTime); System.out.println("Formatted Date: " + formattedDate); System.out.println("Formatted Time: " + formattedTime); } } ``` ## Comparison 1. In java, I have below samples file with pattern \-DDMMYYYY\_HHmmss.csv ``` Test1-04082024_153000.csv Test1-05082024_153000.csv ``` Write a code to compare timestamp and select latest file ```java import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; public class TimestampComparison { private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("ddMMyyyy_HHmmss"); private boolean isNewer(String newFileName, String oldFileName) { String newTimestamp = extractTimestamp(newFileName); String oldTimestamp = extractTimestamp(oldFileName); // Parse the timestamps into LocalDateTime objects LocalDateTime newDateTime = LocalDateTime.parse(newTimestamp, FORMATTER); LocalDateTime oldDateTime = LocalDateTime.parse(oldTimestamp, FORMATTER); // Compare LocalDateTime objects return newDateTime.isAfter(oldDateTime); } private String extractTimestamp(String fileName) { // Extract the part of the filename containing the date and time return fileName.split("-")[1].replace(".csv", ""); } public static void main(String[] args) { TimestampComparison comparison = new TimestampComparison(); System.out.println(comparison.isNewer("Test1-04082024_153000.csv", "Test1-04082024_163000.csv")); // false System.out.println(comparison.isNewer("Test1-05082024_153000.csv", "Test1-04082024_153000.csv")); // true } } ``` --- # Agent Instructions This documentation is published with GitBook. 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