I have two screens where I show a message creation time and date. Initially, there was only one screen and I should always show time and show date differently depending on difference between today and the message creation day.

Here is my method:

private final static String TIME_TEMPLATE_TODAY = "HH:mm";

public static String getFormattedDate(Date msgDate, Date currentTime) {
        long daysDiff = Utils.getDaysDiff(currentTime, msgDate);

        String format;
        if (currentTime.getYear() != msgDate.getYear()) {
            format = "dd.MM.yyyy' at '" + TIME_TEMPLATE_TODAY;
        } else if (daysDiff == 0) {
            format = TIME_TEMPLATE_TODAY;
        } else if (daysDiff == 1) {
            format = "'yesterday at " + TIME_TEMPLATE_TODAY;
        } else if (daysDiff > 1) {
            format = "dd.MM' at '" + TIME_TEMPLATE_TODAY;
        } else {
            format = "dd.MM.yyyy";
            Timber.e("Unexpected time diff: %d", daysDiff);
        }

        return new SimpleDateFormat(format, Locale.CANADA).format(msgDate);
    }

And now I should add cases for the second screen: show time only if it is today, otherwise, show only date (or "yesterday") without time.

I came up with solution below:

public static String getFormattedDate(Date msgDate, Date currentTime, boolean alwaysShowTime) {
        long daysDiff = Utils.getDaysDiff(currentTime, msgDate);
        StringBuilder format = new StringBuilder();

        // Add date representation
        if (currentTime.getYear() != msgDate.getYear()) {
            format.append("dd.MM.yyyy'");
        } else if (daysDiff == 1) {
            format.append("'вчера'");
        } else if (daysDiff > 1) {
            format.append("dd.MM");
        } else {
            format.append("dd.MM.yyyy");
            Timber.e("Unexpected time diff: %d", daysDiff);
        }

        // Add time
        if (daysDiff == 0) {
            format.append(TIME_TEMPLATE_TODAY);
        } else if (alwaysShowTime) {
            format.append("' at '")
                    .append(TIME_TEMPLATE_TODAY);
        }

        return new SimpleDateFormat(format.toString(), Locale.CANADA).format(msgDate);
    }

Disadvantages that I see are:

1. I changed method contract (but it used in 1-2 places, so it is not a big deal in this case)

2. I need to always pass this third parameter to the method. I can solve both points creating another method with a previous contract and pass some default value for alwaysShowTime

3. If some third option appears, I would have to change the contract again, changing Boolean to enum, for example.

What problems or possible optimizations do you see here? Should I just create a new method and extract some common logic to a private method instead changing existing one?