6 weeks are standard. If you want to keep it for longer it needs additives which increase price. Noone does that usually.
"California’s inventory has averaged just over 20 days of supply over the last five years (2019–23), compared with the U.S. average of 21.6 days."
Like, they have 6 weeks, on hand, in tanks already delivered.
But, all of the ships in-bound are now done.
After the war started, there was a record number of ships, already filled, already in-transit. But now they have all reached their destinations. So there is no more incoming.
If it's going down at 1 day per week then it's not so bad. If it's closer to 0.75 days per day, that's much more serious.