How long in advance do you need to show hotel bookings when applying for a visa at the Hanoi embassy?

When applying for a visa at the Hanoi embassy, it appears that showing a hotel booking for one week is generally acceptable, as indicated by a user who successfully applied with a one-week booking. Other users have also noted that showing a shorter duration, such as three days, can still lead to a successful application, suggesting that the length of the hotel booking may not be a significant factor in the visa approval process.