# How to handle missing date data?

I have a column named GarageYrBlt which just lists the year the garage of that house was built. I have one nan value for this column. Does it make sense to fill it with the columns median (This was a common approach for the missing age values in the Titanic competition)?

I believe you have a variable which describes which neighbourhood the house is in. A more focussed approach would be to replace that missing value in GarageYrBlt with the mean / median for that neighbourhood (subject to additional sensibility checks like the garage not being built before the house).