Fix booking time calculation for multi-day flex trip searches

application/src/ext-test/java/org/opentripplanner/ext/flex/template/ClosestTripTest.java

@@ -6,6 +6,7 @@
 import static org.opentripplanner.transit.model._data.TimetableRepositoryForTest.id;
 
 import gnu.trove.set.hash.TIntHashSet;
+import java.time.Instant;
 import java.time.LocalDate;
 import java.util.Collection;
 import java.util.List;
@@ -37,7 +38,8 @@ class ClosestTripTest {
   private static final FlexServiceDate FSD = new FlexServiceDate(
     DATE,
     ServiceDateUtils.secondsSinceStartOfTime(DATE.atStartOfDay(ZoneIds.BERLIN), DATE),
-    10,
+    Instant.ofEpochSecond(10),
+    ZoneIds.BERLIN,
     new TIntHashSet()
   );
   private static final StopLocation STOP = FLEX_TRIP.getStop(0);

application/src/ext-test/java/org/opentripplanner/ext/flex/template/FlexServiceDateBookingTimeTest.java

@@ -0,0 +1,117 @@
+package org.opentripplanner.ext.flex.template;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import org.junit.jupiter.api.Test;
+import org.opentripplanner.transit.model.timetable.booking.RoutingBookingInfo;
+
+/**
+ * Tests for {@link FlexServiceDate#requestedBookingTime()} to verify that booking time
+ * is correctly calculated relative to each service date's start-of-service.
+ */
+class FlexServiceDateBookingTimeTest {
+
+  private static final ZoneId ZONE = ZoneId.of("Europe/Oslo");
+
+  @Test
+  void testRequestedBookingTimeSameDay() {
+    // Booking at 14:00 on Jan 13, service date is Jan 13
+    LocalDate serviceDate = LocalDate.of(2026, 1, 13);
+    Instant bookingTime = ZonedDateTime.of(serviceDate, LocalTime.of(14, 0), ZONE).toInstant();
+
+    FlexServiceDate flexDate = new FlexServiceDate(serviceDate, 0, bookingTime, ZONE, null);
+
+    // Expected: 14:00 = 14 * 3600 = 50400 seconds from start of service
+    int expected = 14 * 3600;
+    assertEquals(expected, flexDate.requestedBookingTime());
+  }
+
+  @Test
+  void testRequestedBookingTimePreviousDay() {
+    // Booking at 14:40 on Jan 12, service date is Jan 13
+    // This is the bug scenario: booking time should be negative relative to Jan 13
+    LocalDate bookingDate = LocalDate.of(2026, 1, 12);
+    LocalDate serviceDate = LocalDate.of(2026, 1, 13);
+
+    Instant bookingTime = ZonedDateTime.of(bookingDate, LocalTime.of(14, 40), ZONE).toInstant();
+
+    FlexServiceDate flexDate = new FlexServiceDate(serviceDate, 0, bookingTime, ZONE, null);
+
+    // Booking is at 14:40 on Jan 12
+    // Service date start is midnight Jan 13 (NOON - 12h)
+    // 14:40 on Jan 12 is 9 hours 20 minutes before midnight Jan 13
+    // = -(9*3600 + 20*60) = -33600 seconds
+    int expected = -(9 * 3600 + 20 * 60);
+    assertEquals(expected, flexDate.requestedBookingTime());
+  }
+
+  @Test
+  void testRequestedBookingTimeMultipleDaysAhead() {
+    // Booking at 10:00 on Jan 10, service date is Jan 13
+    LocalDate bookingDate = LocalDate.of(2026, 1, 10);
+    LocalDate serviceDate = LocalDate.of(2026, 1, 13);
+
+    Instant bookingTime = ZonedDateTime.of(bookingDate, LocalTime.of(10, 0), ZONE).toInstant();
+
+    FlexServiceDate flexDate = new FlexServiceDate(serviceDate, 0, bookingTime, ZONE, null);
+
+    // 10:00 on Jan 10 is 2 days + 14 hours before midnight Jan 13
+    // = -(2*24 + 14) hours = -62 hours = -62 * 3600 seconds = -223200
+    int expected = -((2 * 24 + 14) * 3600);
+    assertEquals(expected, flexDate.requestedBookingTime());
+  }
+
+  @Test
+  void testRequestedBookingTimeNull() {
+    LocalDate serviceDate = LocalDate.of(2026, 1, 13);
+
+    FlexServiceDate flexDate = new FlexServiceDate(serviceDate, 0, null, ZONE, null);
+
+    assertEquals(RoutingBookingInfo.NOT_SET, flexDate.requestedBookingTime());
+  }
+
+  @Test
+  void testBookingTimeOnDifferentDatesProducesDifferentResults() {
+    // Same booking instant should produce different requestedBookingTime values
+    // for different service dates - this is the core fix
+    Instant bookingTime = ZonedDateTime.of(
+      LocalDate.of(2026, 1, 12),
+      LocalTime.of(14, 40),
+      ZONE
+    ).toInstant();
+
+    FlexServiceDate jan12 = new FlexServiceDate(
+      LocalDate.of(2026, 1, 12),
+      0,
+      bookingTime,
+      ZONE,
+      null
+    );
+
+    FlexServiceDate jan13 = new FlexServiceDate(
+      LocalDate.of(2026, 1, 13),
+      0,
+      bookingTime,
+      ZONE,
+      null
+    );
+
+    // On Jan 12: booking at 14:40 = 14*3600 + 40*60 = 52800 seconds
+    assertEquals(14 * 3600 + 40 * 60, jan12.requestedBookingTime());
+
+    // On Jan 13: booking at 14:40 on Jan 12 = -9*3600 - 20*60 = -33600 seconds
+    assertEquals(-(9 * 3600 + 20 * 60), jan13.requestedBookingTime());
+
+    // They must be different!
+    assertEquals(
+      86400,
+      jan12.requestedBookingTime() - jan13.requestedBookingTime(),
+      "Booking time difference should equal one day in seconds"
+    );
+  }
+}

application/src/ext-test/java/org/opentripplanner/ext/flex/template/FlexTemplateFactoryTest.java

@@ -12,6 +12,7 @@
 import java.time.Duration;
 import java.time.LocalDate;
 import java.time.Month;
+import java.time.ZoneId;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Set;
@@ -34,7 +35,6 @@
 import org.opentripplanner.transit.model.site.RegularStop;
 import org.opentripplanner.transit.model.site.StopLocation;
 import org.opentripplanner.transit.model.timetable.Trip;
-import org.opentripplanner.transit.model.timetable.booking.RoutingBookingInfo;
 
 class FlexTemplateFactoryTest {
 
@@ -62,7 +62,8 @@ class FlexTemplateFactoryTest {
   private static final FlexServiceDate DATE = new FlexServiceDate(
     LocalDate.of(2024, Month.MAY, 17),
     SERVICE_TIME_OFFSET,
-    RoutingBookingInfo.NOT_SET,
+    null,
+    ZoneId.of("Europe/Oslo"),
     new TIntHashSet()
   );
 

application/src/ext/java/org/opentripplanner/ext/flex/FlexRouter.java

@@ -36,7 +36,6 @@
 import org.opentripplanner.transit.model.filter.transit.TripMatcherFactory;
 import org.opentripplanner.transit.model.site.StopLocation;
 import org.opentripplanner.transit.model.timetable.Trip;
-import org.opentripplanner.transit.model.timetable.booking.RoutingBookingInfo;
 import org.opentripplanner.transit.service.TransitService;
 import org.opentripplanner.utils.time.ServiceDateUtils;
 
@@ -59,7 +58,8 @@ public class FlexRouter {
   /* Request data */
   private final ZonedDateTime startOfTime;
   private final int requestedTime;
-  private final int requestedBookingTime;
+  private final Instant requestedBookingTimeInstant;
+  private final ZoneId timeZone;
   private final List<FlexServiceDate> dates;
   private final Matcher<Trip> matcher;
 
@@ -117,9 +117,8 @@ public FlexRouter(
     LocalDate searchDate = LocalDate.ofInstant(requestedTime, tz);
     this.startOfTime = ServiceDateUtils.asStartOfService(searchDate, tz);
     this.requestedTime = ServiceDateUtils.secondsSinceStartOfTime(startOfTime, requestedTime);
-    this.requestedBookingTime = requestedBookingTime == null
-      ? RoutingBookingInfo.NOT_SET
-      : ServiceDateUtils.secondsSinceStartOfTime(startOfTime, requestedBookingTime);
+    this.requestedBookingTimeInstant = requestedBookingTime;
+    this.timeZone = tz;
     this.dates = createFlexServiceDates(
       transitService,
       additionalPastSearchDays,
@@ -190,7 +189,8 @@ private List<FlexServiceDate> createFlexServiceDates(
         new FlexServiceDate(
           date,
           ServiceDateUtils.secondsSinceStartOfTime(startOfTime, date),
-          requestedBookingTime,
+          requestedBookingTimeInstant,
+          timeZone,
           transitService.getServiceCodesRunningForDate(date)
         )
       );

application/src/ext/java/org/opentripplanner/ext/flex/template/FlexServiceDate.java

@@ -1,7 +1,13 @@
 package org.opentripplanner.ext.flex.template;
 
 import gnu.trove.set.TIntSet;
+import java.time.Instant;
 import java.time.LocalDate;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import javax.annotation.Nullable;
+import org.opentripplanner.transit.model.timetable.booking.RoutingBookingInfo;
+import org.opentripplanner.utils.time.ServiceDateUtils;
 
 /**
  * This class contains information used in a flex router, and depends on the date the search was
@@ -21,18 +27,39 @@ public class FlexServiceDate {
   /** Which services are running on the date. */
   private final TIntSet servicesRunning;
 
+  /**
+   * The requested booking time as seconds since the start of service for this date.
+   * Calculated relative to this specific service date's start-of-service.
+   */
   private final int requestedBookingTime;
 
   public FlexServiceDate(
     LocalDate serviceDate,
     int secondsFromStartOfTime,
-    int requestedBookingTime,
+    @Nullable Instant requestedBookingTimeInstant,
+    ZoneId timeZone,
     TIntSet servicesRunning
   ) {
     this.serviceDate = serviceDate;
     this.secondsFromStartOfTime = secondsFromStartOfTime;
-    this.requestedBookingTime = requestedBookingTime;
     this.servicesRunning = servicesRunning;
+    this.requestedBookingTime = calculateRequestedBookingTime(
+      serviceDate,
+      timeZone,
+      requestedBookingTimeInstant
+    );
+  }
+
+  private static int calculateRequestedBookingTime(
+    LocalDate serviceDate,
+    ZoneId timeZone,
+    @Nullable Instant requestedBookingTimeInstant
+  ) {
+    if (requestedBookingTimeInstant == null) {
+      return RoutingBookingInfo.NOT_SET;
+    }
+    ZonedDateTime startOfService = ServiceDateUtils.asStartOfService(serviceDate, timeZone);
+    return ServiceDateUtils.secondsSinceStartOfTime(startOfService, requestedBookingTimeInstant);
   }
 
   LocalDate serviceDate() {
@@ -43,6 +70,9 @@ int secondsFromStartOfTime() {
     return secondsFromStartOfTime;
   }
 
+  /**
+   * Get the requested booking time as seconds since the start of service for this date.
+   */
   int requestedBookingTime() {
     return requestedBookingTime;
   }