Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
NumPad2: Unlimited Sprint
NumPad3: Set Time To Day
NumPad4: Set Time To Night
NumPad5: Set Time To Aurora
NumPad6: Set Weather To Clear
NumPad7: Spawn Item (from +350 Items)
NumPad8: Unlimited Weight
NumPad9: Unlock All Feats
NumPad0: All Skills Mastered
NumPad/: Cure All Afflictions
NumPad*: Fly Mode
NumPad-: Reset Cold
NumPad+: Reset Condition
NumPad.: Reset Hunger
Page UP: Reset Fatigue
Page Down: Reset Thirst
Insert: Infinite Durability
Set Weather To Clear: It may takes up to a minute for the weather to change.
Fly Mode: Press SPACE key to exit fly mode.
Spawn Item: Press hotkey to spawn an item. A messagebox opens (so make sure you alt tab to the trainer) where you can select the item to spawn via drop down list. A second messagebox asks for the quantity.
Unlimited Weight: While active you can carry unlimited items. This may reset at some points so just re-enable it in such a case.
Unlock All Feats: Press hotkey and all feats are unlocked.
Unlock more trainer options including updates from here - The Long Dark Trainer