Often said that Jet A1 and diesel are the same stuff
There is a bit more to it. Diesel can have a wax point as high as (I think) about -10 deg C for European summer fuel, but Jet-A1 has to be able to tolerate tank and fuel system temperatures down to about -60 deg C.
Also Diesel is produced to have a specific cetane rating (cf Octane rating) which Jet A1 doesn't need, so usually has a much lower one than Diesel.
In short they are similar, but not the same
Brooklands