diff --git a/lib/src/main/java/dev/doglog/DogLog.java b/lib/src/main/java/dev/doglog/DogLog.java
index e9814a4..91b9f6d 100644
--- a/lib/src/main/java/dev/doglog/DogLog.java
+++ b/lib/src/main/java/dev/doglog/DogLog.java
@@ -137,76 +137,101 @@ public static boolean isEnabled() {
 
   /** Log a boolean array. */
   public static void log(String key, boolean @Nullable [] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, boolean @Nullable [] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a boolean. */
   public static void log(String key, boolean value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, boolean value) {
     if (!enabled) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a double array. */
   public static void log(String key, double @Nullable [] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, double @Nullable [] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a double array with unit metadata. */
   public static void log(String key, double @Nullable [] value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(
+      long timestamp, String key, double @Nullable [] value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
     if (value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   /** Log a double array with unit metadata. */
   public static void log(String key, double @Nullable [] value, @Nullable Unit unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(
+      long timestamp, String key, double @Nullable [] value, @Nullable Unit unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
 
-    log(key, value, unit.name());
+    log(timestamp, key, value, unit.name());
   }
 
   /** Log a double. */
   public static void log(String key, double value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, double value) {
     if (!enabled) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a double with unit metadata. */
   public static void log(String key, double value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(long timestamp, String key, double value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
@@ -215,239 +240,306 @@ public static void log(String key, double value, @Nullable String unit) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   /** Log a double with unit metadata. */
   public static void log(String key, double value, @Nullable Unit unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(long timestamp, String key, double value, @Nullable Unit unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
 
-    log(key, value, unit.name());
+    log(timestamp, key, value, unit.name());
   }
 
   /** Log a measure, preserving the user-specified unit. */
   public static void log(String key, @Nullable Measure<?> value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, @Nullable Measure<?> value) {
     if (!enabled || value == null) {
       return;
     }
 
-    log(key, value.magnitude(), value.unit().name());
+    log(timestamp, key, value.magnitude(), value.unit().name());
   }
 
   /** Log a float array. */
   public static void log(String key, float @Nullable [] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, float @Nullable [] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a float array with unit metadata. */
   public static void log(String key, float @Nullable [] value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(
+      long timestamp, String key, float @Nullable [] value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
     if (value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   /** Log a float. */
   public static void log(String key, float value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, float value) {
     if (!enabled) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a float with unit metadata. */
   public static void log(String key, float value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(long timestamp, String key, float value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   /** Log an int array. */
   public static void log(String key, int @Nullable [] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, int @Nullable [] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a long array. */
   public static void log(String key, long @Nullable [] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, long @Nullable [] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a long array with unit metadata. */
   public static void log(String key, long @Nullable [] value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(
+      long timestamp, String key, long @Nullable [] value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
     if (value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   /** Log a long. */
   public static void log(String key, long value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, long value) {
     if (!enabled) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a long with unit metadata. */
   public static void log(String key, long value, @Nullable String unit) {
+    log(0, key, value, unit);
+  }
+
+  public static void log(long timestamp, String key, long value, @Nullable String unit) {
     if (!enabled) {
       return;
     }
     if (unit == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, unit);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, unit);
   }
 
   // TODO: Raw logs
 
   /** Log a string array. */
   public static void log(String key, @Nullable String[] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, @Nullable String[] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log an enum array. */
   public static <E extends Enum<E>> void log(String key, @Nullable E[] value) {
+    log(0, key, value);
+  }
+
+  public static <E extends Enum<E>> void log(long timestamp, String key, @Nullable E[] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a string. */
   public static void log(String key, @Nullable String value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, @Nullable String value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a string with a custom type string. */
   public static void log(String key, @Nullable String value, @Nullable String customTypeString) {
+    log(0, key, value, customTypeString);
+  }
+
+  public static void log(
+      long timestamp, String key, @Nullable String value, @Nullable String customTypeString) {
     if (!enabled || value == null) {
       return;
     }
 
     if (customTypeString == null) {
-      log(key, value);
+      log(timestamp, key, value);
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value, customTypeString);
+    logger.log(
+        timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value, customTypeString);
   }
 
   /** Log an enum. */
   public static <E extends Enum<E>> void log(String key, @Nullable E value) {
+    log(0, key, value);
+  }
+
+  public static <E extends Enum<E>> void log(long timestamp, String key, @Nullable E value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a struct array. */
   public static <T extends StructSerializable> void log(String key, @Nullable T[] value) {
+    log(0, key, value);
+  }
+
+  public static <T extends StructSerializable> void log(
+      long timestamp, String key, @Nullable T[] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a struct. */
   public static <T extends StructSerializable> void log(String key, @Nullable T value) {
+    log(0, key, value);
+  }
+
+  public static <T extends StructSerializable> void log(
+      long timestamp, String key, @Nullable T value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a record. */
   public static void log(String key, @Nullable Record value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, @Nullable Record value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /** Log a record array. */
   public static void log(String key, @Nullable Record[] value) {
+    log(0, key, value);
+  }
+
+  public static void log(long timestamp, String key, @Nullable Record[] value) {
     if (!enabled || value == null) {
       return;
     }
 
-    var now = HALUtil.getFPGATime();
-    logger.log(now, key, false, value);
+    logger.log(timestamp == 0 ? HALUtil.getFPGATime() : timestamp, key, false, value);
   }
 
   /**
diff --git a/test-project/src/main/java/frc/robot/Robot.java b/test-project/src/main/java/frc/robot/Robot.java
index 225ab6b..c38123a 100644
--- a/test-project/src/main/java/frc/robot/Robot.java
+++ b/test-project/src/main/java/frc/robot/Robot.java
@@ -9,6 +9,7 @@
 
 import com.ctre.phoenix6.hardware.TalonFX;
 import dev.doglog.DogLog;
+import edu.wpi.first.hal.HALUtil;
 import edu.wpi.first.math.kinematics.SwerveModuleState;
 import edu.wpi.first.wpilibj.TimedRobot;
 import edu.wpi.first.wpilibj.sysid.SysIdRoutineLog;
@@ -69,6 +70,42 @@ public void robotPeriodic() {
 
     // An enum that can't be converted to a struct
     DogLog.log("BrokenEnumStruct", SysIdRoutineLog.State.kDynamicForward);
+
+    DogLog.log("Random/RandomLater", Math.random());
+
+    // these should all have the same timestamp
+    long timestamp = HALUtil.getFPGATime();
+    DogLog.log(timestamp, "ts/Debug/SwerveState", new SwerveModuleState());
+    DogLog.log(
+        timestamp,
+        "ts/Debug/SwerveStates",
+        new SwerveModuleState[] {
+          new SwerveModuleState(),
+          new SwerveModuleState(),
+          new SwerveModuleState(),
+          new SwerveModuleState()
+        });
+    DogLog.log(timestamp, "ts/Debug/Position", motor.getPosition().getValueAsDouble());
+    DogLog.log(timestamp, "ts/Debug/Json", "{\"test\": \"json\"}", "json");
+
+    DogLog.log(timestamp, "ts/Tunable/SupplierValue", tunableSupplier.getAsDouble());
+
+    DogLog.log(timestamp, "ts/Random/Random", Math.random());
+
+    DogLog.log(timestamp, "ts/Units/Height1", 123, "inches");
+    DogLog.log(timestamp, "ts/Units/Height2", 123, Meters);
+    DogLog.log(timestamp, "ts/Units/Height3", Centimeters.of(123));
+    DogLog.log(timestamp, "ts/Units/Height4", 123, "Meter");
+    DogLog.log(timestamp, "ts/Units/Height5", 123, "meter");
+    DogLog.log(timestamp, "ts/Units/Height7", motor.getPosition().getValue());
+
+    // An enum that can't be converted to a struct
+    DogLog.log(timestamp, "ts/BrokenEnumStruct", SysIdRoutineLog.State.kDynamicForward);
+
+    DogLog.log(timestamp, "ts/Random/RandomLater", Math.random());
+    DogLog.log(timestamp, "ts/ts", timestamp);
+
+    DogLog.log(timestamp - 1000000, "ts/ts-1", timestamp);
   }
 
   @Override