Timezone Support

src/main/java/ch/njol/skript/conditions/CondIsTimezoneValid.java

@@ -0,0 +1,59 @@
+package ch.njol.skript.conditions;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.doc.*;
+import ch.njol.skript.lang.Condition;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+import java.time.DateTimeException;
+import java.time.ZoneId;
+
+@Name("Is Timezone Valid")
+@Description("Checks if a timezone is valid.")
+@Example("""
+	set {_timezone} to "America/New_York"
+	if {_timezone} is a valid timezone:
+		set {_date} to now in timezone {_timezone}
+	""")
+@Since("INSERT VERSION")
+public class CondIsTimezoneValid extends Condition {
+
+	static {
+		Skript.registerCondition(CondIsTimezoneValid.class, "%strings% (are|is [a[n]]) [negate:in]valid time[ ]zone[s]");
+	}
+
+	private Expression<String> timezones;
+	private boolean isNegated;
+
+	@Override
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		timezones = (Expression<String>) expressions[0];
+		isNegated = parseResult.hasTag("negate");
+		return true;
+	}
+
+	@Override
+	public boolean check(Event event) {
+		return timezones.check(event, CondIsTimezoneValid::isValidTimezone, isNegated);
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return timezones.toString(event, debug) + " are " + (isNegated ? "in" : "") + "valid timezones";
+	}
+
+	private static boolean isValidTimezone(String timezone) {
+		try {
+			ZoneId.of(timezone);
+		} catch (DateTimeException e) {
+			return false;
+		}
+
+		return true;
+	}
+
+}

src/main/java/ch/njol/skript/expressions/ExprAllTimezones.java

@@ -0,0 +1,44 @@
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Example;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.ExpressionType;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.util.SimpleLiteral;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+import java.time.ZoneId;
+
+@Name("All Timezones")
+@Description("Returns a list of all timezones that can be used in the <a href='#ExprDateInTimezone'>date in timezone</a> expression.")
+@Example("set {_timezones::*} to all timezones")
+@Since("INSERT VERSION")
+public class ExprAllTimezones extends SimpleLiteral<String> {
+
+	static {
+		Skript.registerExpression(ExprAllTimezones.class, String.class, ExpressionType.SIMPLE, "all [of [the]] time[ ]zones");
+	}
+
+	private static String[] timezones = ZoneId.getAvailableZoneIds().toArray(new String[0]);
+
+	public ExprAllTimezones() {
+		super(timezones, String.class, true);
+	}
+
+	@Override
+	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		return true;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return "all timezones";
+	}
+
+}

src/main/java/ch/njol/skript/expressions/ExprDateInTimezone.java

@@ -0,0 +1,110 @@
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Example;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.ExpressionType;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.util.SimpleExpression;
+import ch.njol.skript.util.Date;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+import java.time.DateTimeException;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+@Name("Date in Timezone")
+@Description({
+	"Returns a date in the specified timezone. Note that the result date might not be equal to the input date.",
+	"Use <a href='#ExprAllTimezones'>all timezones</a> to get a list of valid timezones."
+})
+@Example("""
+	set {_date} to now in timezone "Europe/Istanbul"
+	set {_clock} to {_date} formatted as "kk:mm"
+	send "It is currently %{_clock}% in Istanbul!" to player
+	""")
+@Since("INSERT VERSION")
+public class ExprDateInTimezone extends SimpleExpression<Date> {
+
+	static {
+		Skript.registerExpression(ExprDateInTimezone.class, Date.class, ExpressionType.SIMPLE,
+			"[the] [date[s]] %dates% in time[ ]zone %string%",
+			"[the] [date[s]] %dates% in [the] %string% time[ ]zone");
+	}
+
+	private Expression<Date> dates;
+	private Expression<String> timezone;
+
+	@Override
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		dates = (Expression<Date>) expressions[0];
+		timezone = (Expression<String>) expressions[1];
+		return true;
+	}
+
+	@Override
+	protected Date @Nullable [] get(Event event) {
+		String timezone = this.timezone.getSingle(event);
+
+		if (timezone == null) {
+			error("Timezone is not set.");
+			return new Date[0];
+		}
+
+		Date[] dates = this.dates.getArray(event);
+
+		for (int i = 0; i < dates.length; i++) {
+			dates[i] = getShiftedDate(dates[i], timezone);
+		}
+
+		return dates;
+	}
+
+	@Override
+	public boolean isSingle() {
+		return dates.isSingle();
+	}
+
+	@Override
+	public Class<? extends Date> getReturnType() {
+		return Date.class;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return "dates " + dates.toString(event, debug) + " in timezone " + timezone.toString(event, debug);
+	}
+
+	/**
+	 * Shifts a date by the given timezone. Meaning if the system timezone is UTC and you give it a GMT+3 timezone,
+	 * it will add 3 hours to the given date.
+	 * @param date The date to shift
+	 * @param timezone The timezone
+	 * @return A new Date
+	 */
+	private Date getShiftedDate(Date date, String timezone) {
+		ZoneId targetZoneId;
+		try {
+			targetZoneId = ZoneId.of(timezone);
+		} catch (DateTimeException e) { // invalid zone format
+			error("Invalid timezone.");
+			return null;
+		}
+
+		Instant instantDate = date.toInstant();
+		ZoneId localZoneId = ZoneId.systemDefault();
+		Instant shiftedNow = ZonedDateTime.ofInstant(instantDate, targetZoneId)
+			.toLocalDateTime()
+			.atZone(localZoneId)
+			.toInstant();
+		java.util.Date javaDate = java.util.Date.from(shiftedNow);
+		return Date.fromJavaDate(javaDate);
+	}
+
+}

src/main/java/ch/njol/skript/expressions/ExprNow.java

@@ -20,34 +20,34 @@
 @Examples({"broadcast \"Current server time: %now%\""})
 @Since("1.4")
 public class ExprNow extends SimpleExpression<Date> {
-	
+
 	static {
 		Skript.registerExpression(ExprNow.class, Date.class, ExpressionType.SIMPLE, "now");
 	}
-	
+
 	@Override
 	public boolean init(final Expression<?>[] exprs, final int matchedPattern, final Kleenean isDelayed, final ParseResult parseResult) {
 		return true;
 	}
-	
+
 	@Override
 	protected Date[] get(final Event e) {
 		return new Date[] {new Date()};
 	}
-	
+
 	@Override
 	public boolean isSingle() {
 		return true;
 	}
-	
+
 	@Override
 	public Class<? extends Date> getReturnType() {
 		return Date.class;
 	}
-	
+
 	@Override
 	public String toString(final @Nullable Event e, final boolean debug) {
 		return "now";
 	}
-	
+
 }

src/main/java/ch/njol/skript/test/platform/Environment.java

@@ -227,6 +227,7 @@ public TestResults runTests(Path runnerRoot, Path testsRoot, boolean devMode, bo
 			args.add("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8000");
 		args.add("-Duser.language=en");
 		args.add("-Duser.country=US");
+		args.add("-Duser.timezone=UTC");
 		args.addAll(jvmArgs);
 		args.addAll(Arrays.asList(commandLine));
 

src/test/skript/tests/misc/timezone.sk

@@ -0,0 +1,17 @@
+test "timezone syntaxes":
+	assert size of all timezones > 0 with "timezones aren't set"
+
+	assert "Europe/Istanbul" is a valid timezone with "single timezone should've been valid"
+	assert ("Europe/Istanbul" and "Asia/Tokyo") are valid timezones with "multiple timezones with 'and' should've been valid"
+	assert ("Europe/Istanbul" or "Asia/Tokyo") is a valid timezone with "multiple timezones with 'or' should've been valid"
+
+	assert "hello!" is an invalid timezone with "single timezone should've been invalid"
+	assert ("hello!" and "hi!") are invalid timezones with "multiple timezones with 'and' should've been invalid"
+	assert ("hello!" or "Asia/Tokyo") is an invalid timezone with "multiple timezones with 'or' should've been invalid"
+
+	set {_d} to date(2030, 6, 4, 7, 23)
+	set {_d.in.nyc} to date(2030, 6, 4, 3, 23)
+	set {_d.in.istanbul} to date(2030, 6, 4, 10, 23)
+
+	assert difference between ({_d} in timezone "America/New_York") and {_d.in.nyc} < 1 second with "returned incorrect date for New York"
+	assert difference between ({_d} in timezone "Europe/Istanbul") and {_d.in.istanbul} < 1 second with "returned incorrect date for Istanbul"