Convert a single number into a readable, formatted time stamp, and back again.

TimeUnit.java

import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;

public enum TimeUnit {
	
    SEC("second", 1, 's'),
    MIN("minute", 60, 'm'),
    HOUR("hour", 3600, 'h'),
    DAY("day", 86400, 'd'),
    WEEK("week", 604800, '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, SEC}; 
    private static final Pattern isLong = Pattern.compile("[0-9]+");
    
    static {
        for(TimeUnit unit : values())
            convertion.put(unit.unit, unit.ms);
    }
    
    private TimeUnit(String name, long ms, char unit) {
        this.name = name;
        this.ms = ms;
        this.unit = unit;
    }
    
    public String addUnit(int x) {
        String r = this.name;
        if(x > 1) r += "s";
        return x+" "+r;
    }
    
    private static long convert(char c) {
        if(convertion.containsKey(c))
        return convertion.get(c);
        return 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.addUnit(t)).append(" ");
                time -= t * unit.ms;
            }
        }
        return sb.toString().trim();
    }
    
    public static long toLong(String s) {
        long fromString = 0;
        for(String t : s.split(" ")) {
            char c = t.charAt(t.length() - 1);
            t = t.substring(0, t.length() - 1);
            if(!isLong.matcher(t).matches())
                continue;
            fromString += Long.parseLong(t) * TimeUnit.convert(c);
        }
        return fromString;
    }
}