This study highlights the time variation of two most important bioclimatic indices inside an IT office building. This way, during one year’s time period, from February 2010 to February 2011, we have recorded the dry-air temperature, air relative humidity and wind speed (although very low in indoor spaces) and consequently calculated the monthly, daily and hourly values of the Temperature-Humidity Index (THI) and the Wind-Chill Index (Wind-chill) with its equivalent air-temperature. The recordings of the data were made by means of an automatic microclimatic indoor station. The results show that quantitative bioclimatic analyses may be useful instruments in assessing the bioclimatic comfort and well-being and the working environmental conditions inside an office building, where artificial microclimates are created. Moreover, we have also applied a specific questionnaire, to which the office occupants answered, and noticed that there is a close correspondence between the optimal values of bioclimatic indices and the subjective perception of well-being and comfort of people in collective environments.