If i decide one month in a year for example 1st Ramazan or 1st Muharrum to give Khums, then every year on same fixed date do i have to give khums? and if yes than what if i left with no money at that date or before that date ? or do i need to keep aside amount of khums before that date comes ? And if after i less saving & expenses of a month and I'm left with some money than i can give khums ?

by

Yes you have to pay khums every year on same date
If nothing left then khums is not wajib but as I mentioned before khums wajib on saving if one dollar left khums is applied and on grocery or stuff which is unused you have to pay khums on that also
Yes khums is wajib

If i decide one month in a year for example 1st Ramazan or 1st Muharrum to give Khums, then every year on same fixed date do i have to give khums? And if yes than what if i left with no money at that date or before that date ? Or do i need to keep aside amount of khums before that date comes ?

by

Yes, you can give khums on the fixed date. On that date if you left no money, khums is not wajib on you.