Why there is no timestamp field in sensor_msgs ?

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Hi !

I've been looking into ROS2 sensor_msgs definitions for example sensor_msgs::msg::Imu and I see that there is no field for timestamp !

What is the reason for that ? In practice any measurement information must / could be associated with a timestamp for obvious reasons.

Even if IMUs typically don't provide built-int timestamps, the driver node who reads the IMU and publishes the IMU messages could attach a timestamp to the information.

It would make so many thing so much thing easier.... thanks, g