Introduction. This study presents temporal variations of depression-related health information behaviour in a discussion forum. The dimension of time has previously been overlooked within health information behaviour research, and information science in general. Adding this dimension, we propose, can reveal interesting insights. Method. The open data of the discussion forum of Suomi24, the largest and most popular discussion forum in Finland, was utilized to analyse the time stamps of all messages in the depression subcategory. Analysis. All 116,781 messages within the depression sub-category, ranging from 1.1.2001 to 14.5.2015, were processed in JSON format, and analysed using Python. A quantitative analysis and comparison to all other messages, as well as messages in the health category was conducted. Results. Messages posted in the depression subcategory of the Suomi24 discussion forum follow clear and recurring temporal patterns. Significant peaks are visible on different timescales, during the night time, on Monday and Thursday, as well as in spring and autumn. These results are compared to previous research on the dimension of time in relation to depression as well as information science. Conclusion. Adding the dimension of time can reveal interesting new insights on health information behaviour, especially for stigmatised health issues like depression. Knowledge of the temporal nature of depression-related behaviour can aid early intervention, which can be beneficial for positive health outcomes.