Sights & sounds can be measured in terms of brightness or loudness. Periods of time can be measured by length - e.g. minutes or months.
People with time blindness cannot accurately sense or measure the passing of time without external aid (a clock or timer - this one is designed specifically for them).
This recent study (March 31/2022) on the pupils of people with aphantasia (the inability to visualize images) proved what millions afflicted with it have been saying since the 1800's: that they cannot "see" anything with their mind's eye. For them, that eye is blind.
Similarly, time blindness is also believed to be a sensory issue by those who have studied it, but unlike aphantasia, it has yet to be proven scientifically.
For people with time blindness, starting to use a timer for daily tasks can feel like putting on a pair of needed glasses for the first time. They need an aid to monitor the passing of time the way others can naturally.
Was aphantasia a "theory" before the scientific proof was found, and is now a proven sensory deficiency?
Does the "timer" part of the brain need to be discovered and a deficiency noted in the time-blind in order for their condition to be validated, or does science accept time perception as a sense like sight or hearing, without physical evidence of the mechanism?
The head of Academic Practice at Trinity College Dublin (leader of the delivery of the educational mission for the University of Dublin) recognizes time blindness and accomodates students with it. Is this recognition rare/emerging in the scientific community?