I heard R’ Yosef Veiner discuss this question and he said that if you can say Tehillim during the day instead, it would be better. But if, you will not do it during the day or you will waste that time at night, its better to say Tehillim at night.
If one has a Tehillim group and it can be changed to during the day (or Thursday night), better to do that. But if even one person will stop coming, better to keep doing it at night.
This Shiur can be found on Kol HaLashon under Tefilla.