Importing dates from spreadsheets in Ruby

I encountered an interesting issue yesterday. While importing data present in an xlsx file, I noticed that dates present in the excel file were being imported as numerical floats. My original code below

2.upto(10) do |i|
  excel_file ="#{Rails.root}/temp/final_cand/khi_counsel_list.xlsx")
  date_ar = excel_file.cell(i, DATE_COL).to_formatted_s(:long)

After a quick google, I found out that the float being returned was the number of days that have elapsed since (Dec 30, 1899). As to why this is the case, I have no clue and didn't look it up.

I went ahead and modified my code to the following after which everything started working fine.

date_ar = (,12,30) + excel_file.cell(i, DATE_COL).days).to_date.to_formatted_s(:long)