Converting longs to nice time Strings and back

TimeUnit

public enum TimeUnit
{
    S("second", 1000, 's'),
    MIN("minute", 60000, 'm'),
    HOUR("hour", 3600000, 'h'),
    DAY("day", 86400000, 'd'),
    WEEK("week", 604800000, 'w')
    ;
    
    private final String name;
    private final long ms;
    private final char unit;
    
    private static final Map<Character, Long> convertion = new HashMap<Character, Long>();
    
    private static final TimeUnit[] order = new TimeUnit[]{WEEK, DAY, HOUR, MIN, S};
    
    private static final Pattern isLong = Pattern.compile("[0-9]+");
    
    private TimeUnit(String name, long ms, char unit)
    {
        this.name = name;
        this.ms = ms;
        this.unit = unit;
    }
    
    static
    {
        for(TimeUnit unit : values())
            convertion.put(unit.unit, unit.ms);
    }
    
    public String toString(int x)
    {
        String r = this.name;
        if(x > 1)
            r += "s";
        return x+" "+r;
    }
    
    private static long convert(char c)
    {
        return convertion.getOrDefault(c, 0);
    }
    
    public static String toString(long time)
    {
        StringBuilder sb = new StringBuilder();
        int t;
        for(TimeUnit unit : order)
        {
            if(time > unit.ms)
            {
                t = (int) Math.floor((double)time / (double)unit.ms);
                sb.append(unit.toString(t)).append(" ");
                time -= t * unit.ms;
            }
        }
        return sb.toString().trim();
    }
    
    public static long toLong(String s)
    {
        long cooldown = 0;
        String[] time = s.split(" ");
        for(String t : time)
        {
            char c = t.charAt(t.length() - 1);
            t = t.substring(0, t.length() - 1);
            if(!isLong.matcher(t).matches())
                continue;
            cooldown += Long.parseLong(t) * TimeUnit.convert(c);
        }
        return cooldown;
    }
}