All times and dates that are displayed in Neo are formatted according to the language that you have selected, except for time input fields, e.g. fields where you enter a start and end time.
The format of these fields, i.e. if times are shown in 24-hour format or with AM/PM, is determined by the date and time format settings in your operating system (e.g. Windows or Mac OS).
Change date and time format in Windows 10
On Windows 10, you can change the time format under Settings → Time & Language → Region → Change data formats. Change the time format under Short time and Long time to your desired format. Restart your browser. Now the time input fields in Neo should display according to your preferences.
Change date and time format in Mac OS
In Mac OS, the time format in Neo is determined by a combination of the chosen Preferred language and selection in "Time format: 24-Hour Time" under Settings → Language & Region. First, you must select a Preferred language which has your preferred time format as standard, and secondly, you must ensure that "Time format: 24-Hour Time" is set according to your preference. Restart your browser. Now the time input fields in Neo should display according to your preferences.