Holds all the timezones as well as their offsets, for platforms that don't have http://msdn.microsoft.com/en-us/library/system.timezoneinfo.getsystemtimezones(v=vs.110).aspx (like Windows Phone)

TimeZone.cs

using Newtonsoft.Json;

namespace TimeZones
{
    public class TimeZone
    {
        [JsonProperty("Name")]
        public string Name { get; set; }

        [JsonProperty("Offset")]
        public string Offset { get; set; }
    }
}

TimeZones.json

[{
	"Name": "(UTC-12:00) International Date Line West",
	"Offset": "-12:00:00"
},
{
	"Name": "(UTC-11:00) Co-ordinated Universal Time-11",
	"Offset": "-11:00:00"
},
{
	"Name": "(UTC-10:00) Hawaii",
	"Offset": "-10:00:00"
},
{
	"Name": "(UTC-09:00) Alaska",
	"Offset": "-09:00:00"
},
{
	"Name": "(UTC-08:00) Baja California",
	"Offset": "-08:00:00"
},
{
	"Name": "(UTC-08:00) Pacific Time (US & Canada)",
	"Offset": "-08:00:00"
},
{
	"Name": "(UTC-07:00) Arizona",
	"Offset": "-07:00:00"
},
{
	"Name": "(UTC-07:00) Chihuahua, La Paz, Mazatlan",
	"Offset": "-07:00:00"
},
{
	"Name": "(UTC-07:00) Mountain Time (US & Canada)",
	"Offset": "-07:00:00"
},
{
	"Name": "(UTC-06:00) Central America",
	"Offset": "-06:00:00"
},
{
	"Name": "(UTC-06:00) Central Time (US & Canada)",
	"Offset": "-06:00:00"
},
{
	"Name": "(UTC-06:00) Guadalajara, Mexico City, Monterrey",
	"Offset": "-06:00:00"
},
{
	"Name": "(UTC-06:00) Saskatchewan",
	"Offset": "-06:00:00"
},
{
	"Name": "(UTC-05:00) Bogota, Lima, Quito",
	"Offset": "-05:00:00"
},
{
	"Name": "(UTC-05:00) Eastern Time (US & Canada)",
	"Offset": "-05:00:00"
},
{
	"Name": "(UTC-05:00) Indiana (East)",
	"Offset": "-05:00:00"
},
{
	"Name": "(UTC-04:30) Caracas",
	"Offset": "-04:30:00"
},
{
	"Name": "(UTC-04:00) Asuncion",
	"Offset": "-04:00:00"
},
{
	"Name": "(UTC-04:00) Atlantic Time (Canada)",
	"Offset": "-04:00:00"
},
{
	"Name": "(UTC-04:00) Cuiaba",
	"Offset": "-04:00:00"
},
{
	"Name": "(UTC-04:00) Georgetown, La Paz, Manaus, San Juan",
	"Offset": "-04:00:00"
},
{
	"Name": "(UTC-04:00) Santiago",
	"Offset": "-04:00:00"
},
{
	"Name": "(UTC-03:30) Newfoundland",
	"Offset": "-03:30:00"
},
{
	"Name": "(UTC-03:00) Brasilia",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-03:00) Buenos Aires",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-03:00) Cayenne, Fortaleza",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-03:00) Greenland",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-03:00) Montevideo",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-03:00) Salvador",
	"Offset": "-03:00:00"
},
{
	"Name": "(UTC-02:00) Co-ordinated Universal Time-02",
	"Offset": "-02:00:00"
},
{
	"Name": "(UTC-02:00) Mid-Atlantic - Old",
	"Offset": "-02:00:00"
},
{
	"Name": "(UTC-01:00) Azores",
	"Offset": "-01:00:00"
},
{
	"Name": "(UTC-01:00) Cape Verde Is.",
	"Offset": "-01:00:00"
},
{
	"Name": "(UTC) Casablanca",
	"Offset": "00:00:00"
},
{
	"Name": "(UTC) Co-ordinated Universal Time",
	"Offset": "00:00:00"
},
{
	"Name": "(UTC) Dublin, Edinburgh, Lisbon, London",
	"Offset": "00:00:00"
},
{
	"Name": "(UTC) Monrovia, Reykjavik",
	"Offset": "00:00:00"
},
{
	"Name": "(UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+01:00) Brussels, Copenhagen, Madrid, Paris",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+01:00) Sarajevo, Skopje, Warsaw, Zagreb",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+01:00) West Central Africa",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+01:00) Windhoek",
	"Offset": "01:00:00"
},
{
	"Name": "(UTC+02:00) Athens, Bucharest",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Beirut",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Cairo",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Damascus",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) E. Europe",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Harare, Pretoria",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Istanbul",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Jerusalem",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+02:00) Tripoli",
	"Offset": "02:00:00"
},
{
	"Name": "(UTC+03:00) Amman",
	"Offset": "03:00:00"
},
{
	"Name": "(UTC+03:00) Baghdad",
	"Offset": "03:00:00"
},
{
	"Name": "(UTC+03:00) Kaliningrad, Minsk",
	"Offset": "03:00:00"
},
{
	"Name": "(UTC+03:00) Kuwait, Riyadh",
	"Offset": "03:00:00"
},
{
	"Name": "(UTC+03:00) Nairobi",
	"Offset": "03:00:00"
},
{
	"Name": "(UTC+03:30) Tehran",
	"Offset": "03:30:00"
},
{
	"Name": "(UTC+04:00) Abu Dhabi, Muscat",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:00) Baku",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:00) Moscow, St. Petersburg, Volgograd",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:00) Port Louis",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:00) Tbilisi",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:00) Yerevan",
	"Offset": "04:00:00"
},
{
	"Name": "(UTC+04:30) Kabul",
	"Offset": "04:30:00"
},
{
	"Name": "(UTC+05:00) Ashgabat, Tashkent",
	"Offset": "05:00:00"
},
{
	"Name": "(UTC+05:00) Islamabad, Karachi",
	"Offset": "05:00:00"
},
{
	"Name": "(UTC+05:30) Chennai, Kolkata, Mumbai, New Delhi",
	"Offset": "05:30:00"
},
{
	"Name": "(UTC+05:30) Sri Jayawardenepura",
	"Offset": "05:30:00"
},
{
	"Name": "(UTC+05:45) Kathmandu",
	"Offset": "05:45:00"
},
{
	"Name": "(UTC+06:00) Astana",
	"Offset": "06:00:00"
},
{
	"Name": "(UTC+06:00) Dhaka",
	"Offset": "06:00:00"
},
{
	"Name": "(UTC+06:00) Ekaterinburg",
	"Offset": "06:00:00"
},
{
	"Name": "(UTC+06:30) Yangon (Rangoon)",
	"Offset": "06:30:00"
},
{
	"Name": "(UTC+07:00) Bangkok, Hanoi, Jakarta",
	"Offset": "07:00:00"
},
{
	"Name": "(UTC+07:00) Novosibirsk",
	"Offset": "07:00:00"
},
{
	"Name": "(UTC+08:00) Beijing, Chongqing, Hong Kong SAR, Urumqi",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+08:00) Krasnoyarsk",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+08:00) Kuala Lumpur, Singapore",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+08:00) Perth",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+08:00) Taipei",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+08:00) Ulaanbaatar",
	"Offset": "08:00:00"
},
{
	"Name": "(UTC+09:00) Irkutsk",
	"Offset": "09:00:00"
},
{
	"Name": "(UTC+09:00) Osaka, Sapporo, Tokyo",
	"Offset": "09:00:00"
},
{
	"Name": "(UTC+09:00) Seoul",
	"Offset": "09:00:00"
},
{
	"Name": "(UTC+09:30) Adelaide",
	"Offset": "09:30:00"
},
{
	"Name": "(UTC+09:30) Darwin",
	"Offset": "09:30:00"
},
{
	"Name": "(UTC+10:00) Brisbane",
	"Offset": "10:00:00"
},
{
	"Name": "(UTC+10:00) Canberra, Melbourne, Sydney",
	"Offset": "10:00:00"
},
{
	"Name": "(UTC+10:00) Guam, Port Moresby",
	"Offset": "10:00:00"
},
{
	"Name": "(UTC+10:00) Hobart",
	"Offset": "10:00:00"
},
{
	"Name": "(UTC+10:00) Yakutsk",
	"Offset": "10:00:00"
},
{
	"Name": "(UTC+11:00) Solomon Is., New Caledonia",
	"Offset": "11:00:00"
},
{
	"Name": "(UTC+11:00) Vladivostok",
	"Offset": "11:00:00"
},
{
	"Name": "(UTC+12:00) Auckland, Wellington",
	"Offset": "12:00:00"
},
{
	"Name": "(UTC+12:00) Co-ordinated Universal Time+12",
	"Offset": "12:00:00"
},
{
	"Name": "(UTC+12:00) Fiji",
	"Offset": "12:00:00"
},
{
	"Name": "(UTC+12:00) Magadan",
	"Offset": "12:00:00"
},
{
	"Name": "(UTC+12:00) Petropavlovsk-Kamchatsky - Old",
	"Offset": "12:00:00"
},
{
	"Name": "(UTC+13:00) Nuku'alofa",
	"Offset": "13:00:00"
},
{
	"Name": "(UTC+13:00) Samoa",
	"Offset": "13:00:00"
}]