You can book 3days to 4days mount Meru trekking

Mount Meru is the topographic core of Arusha National park. Its abundant hills overhead the adjacent savanna and provision woodland that crowds various wildlife including approximately 400 types of animals and also monkeys and leopards

It is the second-highest mountain in Tanzania, after Mount Kilimanjaro. The Momella route – which starts at Momella gate, on the eastern side of the mountain – is used to climb Mount Meru.