Is it related to a Form, or Workflow? If Workflow - have you tried to click that small "Fx" icon next to a field, and there choose the "ISO" format? Per my experience this is the most secure format to have the date/time field updated.
Regards,
Tomasz
Hi Tomasz,
Thanks for your response but mine is related to a form.
If you want to change the date and time every time you change date/time in other field (before saving the form) than you will have to use the calculated control instead of date/time control.
If you want the default value then may be you can connect the control to the field and then try to manipulate default date/time using Calculated value option in the column settings.
Date/Time control do not have option to display calculated default date without connecting to the column and use column's settings.
Regards,
Kunal