lt2ut.des Be sure that your header records in ou_heade.ok are correct. This includes both the time zone and the dates that they are effective, such as start and end year/month. The start and end dates (YRMO) are after column 80. Be sure that you check both the input (local time) file and the output (UT) file. Check the NUT file to be sure that the day displayed there is actually day one (1) and not represented as day two (2).