getline() does not work if used after some inputs

Adding to what @DavidHammen said:

The extraction operations leave the trailing '\n' character in the stream. On the other hand, istream::getline() discards it. So when you call getline after an extraction operator, '\n' is the first character it encounters and it stops reading right there.

Put this after before getline call extraction:

cin.ignore()

A more robust way of taking input would be something like this:

while (true) {

    cout<<"Time:\t";
    if (cin>>time) {
        cin.ignore();  // discard the trailing '\n'
        break;
    } else {
        // ignore everything or to the first '\n', whichever comes first
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cin.clear();  // clear the error flags
        cout << "Invalid input, try again.\n";
    }
}

Characters are extracted until either (n - 1) characters have been extracted or the delimiting character is found (which is delimiter if this parameter is specified, or '\n' otherwise). The extraction also stops if the end of the file is reached in the input sequence or if an error occurs during the input operation.

When cin.getline() reads from the input, there is a newline character left in the input stream, so it doesn't read your c-string. Use cin.ignore() before calling getline().

cout<<"Journal Entry:\t";
cin.ignore();
cin.getline(journal,23);