A crucial component of forensic serology is determining the age of biological fluids found at crime scenes, which provides information on the chronology of criminal activity. Reconstructing events and supporting alibis are made easier with accurate time determination, which has a big influence on court cases. Developments in biochemical, molecular, and spectroscopic methods over time have opened up new ways to comprehend how bodily fluids including blood, saliva, semen, and perspiration change over time. The current approaches are examined in this review, including oxidative stress markers, protein and RNA degradation, enzymatic degradation, and newly discovered molecular biomarkers. The sensitivity and dependability of methods like spectroscopy, mass spectrometry, and forensic proteomics in determining stain age have been emphasized. These methods do not, however, come without difficulties, including biological factors, substrate interactions, and environmental impacts. variability, which may make aging projections less accurate. In order to improve accuracy and consistency, this study also explores the shortcomings of current approaches and suggests potential future possibilities, such as multi-modal analysis and artificial intelligence. The study concludes by highlighting the necessity of internationally recognized procedures to lessen variation in forensic examinations. In order to lay the groundwork for future developments in this crucial field of forensic science, this study attempts to compile the current status of research on body fluid aging and time estimation.