Thread: Is it possible to make Lucid dreams feel like they have lasted for days?

Well, if you mean feeling that a longer period of time has passed even though this isn't the case in real life, nor the dream, then yes, it's very possible, but it's just a psychological effect, nothing more (kinda like when you feel bored, you feel like that time passes slowly...) However I doubt this effect would have such a huge impact on your perception of time.
If you mean that your perception of passing events actually becomes hyper-activated or something like that, leading you to experience events that would otherwise take a huge amount of time in a relatively small time frame, then it's complicated; research has been conducted on the matter, where participants that were having lucid dreams communicated with the researchers via eye movement and their responses were recorded in real time; which suggests that no, dreams can't be experienced that way. However, there are people who claim that they have dreams where time dialiation actually occurs, although whether their claims are true or not remains unknown.