How to convert CSV/Excel weather file to ddy?

Hi, I have an Excel format of weather file for a certain day and I would like to convert it to DDY and upload it in OpenStudio. How can this be achieved? Thanks in advance, Yael

It sounds like you may be confusing design condtions (.ddy file) with weather (.epw file). See the answer to this question on design conditions vs. weather, and this question for which design day conditions to use for your model.

What you probably want is the ASHRAE 2013 design day information for your site. You can download that here or here.

If you want to adjust the .ddy files, you can could calculate the 0.4%, 1%, 99%, and 99.6% percentiles in your weather file and then adjust the SizingPeriod:DesignDay objects accordingly or make your own.