Dolphin has many places where Modify time, Access time, Creation time is displayed, why Change time was not implemented? I need it.
This feature is not implemented as it was I believe never asked as it is a rather unusual use case. You can use touch to achieve this : https://www.thegeekstuff.com/2012/11/linux-touch-command/
So I am asking about it, unusual or not, but it costs nothing to implement because what time to display is up to a user. Many things that have already been implemented can be attributed to "unusual use case". And touch is for changing timestamps, not displaying them.
I misunderstood you, you meant "Change time" stat's ctime or "status change time". Well, this is not very useful for most users. A patch or rather patches could be accepted (it would require update to kio, dolphin and baloo-widgets at least). It has the history of being mistaken with the creation time because of its name in stat syscall "ctime".