How early could gas turbines arrive?

How early might gas turbines emerge in this alternate timeline?

Earlier funding for Whittle or comparable work could accelerate development, but a working turbine would still take time and no date can be fixed.

The gas-turbine timetable depends on which projects receive funding. Earlier support for Whittle provides one possible route to jet-turbine development. Even with that support, the machinery would take time to mature. The scenario leaves the result open and gives no year for a breakthrough.