It depends on the operator, the wind forecast vendors used, and individual pilots.
Most airplanes with ACARS have the ability to upload forecast winds at any time before and during flight. If ACARS is not available, winds from the flight plan will be used, which may be as much as 20 hours old at the end of a long flight.
Those who update the winds inflight can get forecasts less than 4 hours old. Forecast altitudes depend on company SOPs and pilot input preferences.