After closing the file without saving it, the modification date of the file is changed. Why is it so?
When closing a model, the view/window setting is saved as backup by default. For this reason, the modification date is changed too. If you want to avoid this, deactivate this function in the "Program" tab of the "Program Options" window.
save, modification date, date
Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements
The structural engineering software for design of frame, beam and truss structures, performing linear and nonlinear calculations of internal forces, deformations, and support reactions