For 5 days, its bearable. 4 days via Siwan, and 1 day via Narkatiaganj. Rest 2 days, via Mau, it is about 1h 20m slow so yeah, some time goes for these 2 days. On Friday, there's an alternative as well. ASN GKP which could be taken if the passenger wants to stay at station for 4 hrs, by taking TATA DNR to ASN and then ASN GKP