I calculated it from Aston university stop because of a misunderstanding of post#17247
We then board the 1633 Arriva Midlands 'Sapphire' service 110 to Aston University (Bagot Street), arriving there at 1731 on Sunday afternoon.
We leave the station and board the 16:46 London United route 18 service to Sudbury & Harrow Road Station, arriving there at 18:06 on a Monday.
Do we need to allow the minimum fifteen minute connection time at Euston?
We walk 7mins to Sudbury Town where we board the 18:16 Piccadilly service to Ruislip Manor arriving at 18:28 Monday.We leave the station and board the 16:46 London United route 18 service to Sudbury & Harrow Road Station, arriving there at 18:06 on a Monday.
We then take the 2207 Victoria Line service to Green Park arriving at 2300 on Monday.
EditedThe Victoria Line doesn't serve Heathrow.
We leave the station and board the 23:10 Arriva London route 38 service to Clapton, Lea Bridge Roundabout, arriving there at 00:07 on a Tuesday.We then take the 2207 Piccadilly Line service to Green Park arriving at 2300 on Monday.
We Board the 23:15 Piccadilly Service to Hillingdon arriving at 00:09 in the early hours of Tuesday.