ASN NJP used to run from ASN only for a very long time, most probably 3 or 4years, with train number 5711/12. I have travelled in that train many times in that train in my childhood. It used to leave ASN around 7 am in the morning and reach NJP by evening, again in the return, it used to leave NJP in the morning hours around 6.30 or 7 and used to reach ASN in the evening at 6pm
Later in 2004, it got extended to RNC with the present TT. Also that time many trains of NJP got an extension to APDJ to decongest NJP. This train also got extended to APDJ with the same purpose along with Mahananda exp and...
more... it number changed to 5661/62. Later got an extension to KYQ with the present train number and days of run
And BTW ASN has now crossed the 60r benchmark, which is benchmark of being an A1 station, back in 2016