No - you cannot have a day + time it in a single cell and expecting that it is recocognized as a date (for LibreOffice locale date acceptance patterns see Tools -> Options -> Language Settings -> Languages in category Language Of) and thus sorted in natural order. In addition - at least for my gut feeling - you are mixing the concepts of 'filter' and 'sort' (I find it a bit confusing that filter dialog shows "Sort De-/Ascending" entries). If I'd need to do your sheet, I'd introduce two columns - One headed "Day" and the other one headed "Time". Now add "Mon", "Tue" etc under colum "Day" and to sort use Data -> Sort .. and under options use Custom sort order to get what you want:
No - you cannot have a day + time it in a single cell and expecting that it is recocognized recognized as a date (for LibreOffice locale date acceptance patterns see Tools -> Options -> Language Settings -> Languages in category Language Of) and thus sorted in natural order. In addition - at least for my gut feeling - you are mixing the concepts of 'filter' and 'sort' (I find it a bit confusing that filter dialog shows "Sort De-/Ascending" entries). If I'd need to do your sheet, I'd introduce two columns - One headed "Day" and the other one headed "Time". Now add "Mon", "Tue" etc under colum "Day" and to sort use Data -> Sort .. and under options use Custom sort order to get what you want: