Forty is a very Biblical number. It rained 40 days and 40 nights during the flood. The children of Israel spent 40 years wandering around the wilderness. David reigned as King for 40 years. After his baptism, Jesus was led by the Spirit into the wild to fast for 40 days before he began his ministry. Usually, 40 was representative of the complete and total time an event lasted, whether or not it was literally and exactly 40 days or years.
Our family has 40 days left in Ireland. For us it is literally 40 days until we complete the entirety of our sojourn on this little green isle. A lot can happen in 40 years or even 40 days. Lord, make it rain, but not literally! - Shay