Off peak day return + travelcard validity

[zero]

With a Z1-4 travelcard on oyster, and an Off peak day return from Mill Hill Broadway to Luton:

Is the earliest valid train the 2348 from St Pancras the day before? (arriving Mill Hill 0006)
Is the latest valid train to St Pancras the 0326 the day after? (arriving Mill Hill 0355)

(If the answer is no, ignore the following.)
The next train from Luton is the 0406 which arrives at Mill Hill at 0435. If a guard happened to be working on this train and applying the rules strictly, would a penalty fare be charged, or could he sell a single from Radlett to BZ4?

If this train happened to travel direct from St Albans (0421) to West Hampstead (0444) with no specified time at which it entered zone 4, would the original ticket + travelcard still be valid?

Thanks

 

[clagmonster]

With a Z1-4 travelcard on oyster, and an Off peak day return from Mill Hill Broadway to Luton:

Is the earliest valid train the 2348 from St Pancras the day before? (arriving Mill Hill 0006)

The ticket carries restriction TN. See: http://www.nationalrail.co.uk/pdfs/CDR_TN.pdf
You are not valid until the 09:04 from Mill Hill on weekdays. This is the 08:44 from St. Pancras. You are unrestricted at weekends, so the first train that the ticket would be valid on would be the first train to leave Mill Hill after midnight.

Is the latest valid train to St Pancras the 0326 the day after? (arriving Mill Hill 0355)

As I understand it, travel must be completed by 04:29 the day after the date on the ticket, so your ticket would be valid on the train you describe.

The next train from Luton is the 0406 which arrives at Mill Hill at 0435. If a guard happened to be working on this train and applying the rules strictly, would a penalty fare be charged, or could he sell a single from Radlett to BZ4?

I see no reason why you would not be able to end your use of your ticket at Radlett at 04:26. If there are facilities at Luton to purchase a Radlett-Mill Hill (or Boundary Zone 4, I don't know whether there is a price difference) then you must use them. If such facilities do not exist, but there is a TVM or PERTis selling other tickets, then Condition 3 kicks in:
"3. Where the full range of tickets is not available
If you cannot buy an appropriate ticket for the journey you want to make because the
range of tickets that is available at the station from which you intend to start your journey
is restricted, you must buy a ticket or Permit to Travel before you travel that entitles you to
make at least part of the journey. Then you must, as soon as is reasonably practicable, buy
an appropriate ticket to complete your journey. In these circumstances, you only need to pay
the fare that you would have paid if you had bought a ticket immediately before your journey.
The price you will have to pay will be reduced by the amount paid for the ticket or Permit to
Travel."
http://www.nationalrail.co.uk/system/galleries/download/misc/NRCOC.pdf
As a single ticket from Radlett to Mill Hill coats £4.10, I would suggest a single from Luton to Luton Airport Parkway, priced at £3.70.

If this train happened to travel direct from St Albans (0421) to West Hampstead (0444) with no specified time at which it entered zone 4, would the original ticket + travelcard still be valid?

Said train seems to call at Radlett, so it is exactly as above. If the train was non-stop, I would advise that the ticket dated for the previous day would be valid as far as the last timing point before 04:29. Detailed times can be found at:
http://www.opentraintimes.com/search/advanced

 

[hairyhandedfool]

....The next train from Luton is the 0406 which arrives at Mill Hill at 0435. If a guard happened to be working on this train and applying the rules strictly, would a penalty fare be charged, or could he sell a single from Radlett to BZ4?....

FCC don't have guards, they have RPIs (and some RPIs do love Penalty Fares), however, if Luton ticket office was closed when you travelled, and the self service machines can't issue the ticket you require for your journey, they should not issue a penalty fare.

This does not mean you can buy a ticket in the morning, knowing you can't use it for your journey later, in an attempt to avoid paying the correct fare.
--- old post above --- --- new post below ---

....As a single ticket from Radlett to Mill Hill coats £4.10, I would suggest a single from Luton to Luton Airport Parkway, priced at £3.70....

If they have a ticket for part of the journey, I don't believe they should have to buy a ticket for the part of the journey for which they already hold a ticket.