The article announces the release of MEGA6, an advanced version of the Molecular Evolutionary Genetics Analysis software. MEGA6 introduces new features for building molecular evolutionary trees scaled to time (timetrees), including the implementation of the RelTime method for estimating divergence times. The software now includes a Timetree Wizard, a graphical user interface that simplifies the process of specifying phylogenies and calibration constraints. Enhanced algorithms improve the search for optimal trees under evolutionary criteria, and memory management has been improved to support larger sequence datasets. Both GUI and command-line versions of MEGA6 are available for free download from www.megasoftware.net. Key enhancements include the ability to convert relative times to absolute times using calibration points, confidence intervals for time estimates, and the addition of the SPR and TBR algorithms for tree optimization. The software also supports 64-bit systems and has a usage analytics system to track user preferences.The article announces the release of MEGA6, an advanced version of the Molecular Evolutionary Genetics Analysis software. MEGA6 introduces new features for building molecular evolutionary trees scaled to time (timetrees), including the implementation of the RelTime method for estimating divergence times. The software now includes a Timetree Wizard, a graphical user interface that simplifies the process of specifying phylogenies and calibration constraints. Enhanced algorithms improve the search for optimal trees under evolutionary criteria, and memory management has been improved to support larger sequence datasets. Both GUI and command-line versions of MEGA6 are available for free download from www.megasoftware.net. Key enhancements include the ability to convert relative times to absolute times using calibration points, confidence intervals for time estimates, and the addition of the SPR and TBR algorithms for tree optimization. The software also supports 64-bit systems and has a usage analytics system to track user preferences.