Convert UTC to "local" time in Go

Your approach is flawed. A country can have several time zones, for example, US and Russia. Because of daylight saving time (DST), a time zone can have more than one time, for example, Hungary. Hungary is UTC +1:00 and is also UTC+2:00 for DST.

For each location that you want the local time for a given UTC time, use the IANA (tzdata) time zone location. For example,

package main

import (
    "fmt"
    "time"
)

func main() {
    utc := time.Now().UTC()
    fmt.Println(utc)
    local := utc
    location, err := time.LoadLocation("Europe/Budapest")
    if err == nil {
        local = local.In(location)
    }
    fmt.Println("UTC", utc.Format("15:04"), local.Location(), local.Format("15:04"))
    local = utc
    location, err = time.LoadLocation("America/Los_Angeles")
    if err == nil {
        local = local.In(location)
    }
    fmt.Println("UTC", utc.Format("15:04"), local.Location(), local.Format("15:04"))
}

Output:

2014-08-14 23:57:09.151377514 +0000 UTC
UTC 23:57 Europe/Budapest 01:57
UTC 23:57 America/Los_Angeles 16:57

References:

IANA Time Zone Database

tz database

tz database time zones

Time zone

Time in Hungary

Keep in mind that the playground has the time set to 2009-11-10 23:00:00 +0000 UTC, so it is working.

The proper way is to use time.LoadLocation though, here's an example:

var countryTz = map[string]string{
    "Hungary": "Europe/Budapest",
    "Egypt":   "Africa/Cairo",
}

func timeIn(name string) time.Time {
    loc, err := time.LoadLocation(countryTz[name])
    if err != nil {
        panic(err)
    }
    return time.Now().In(loc)
}

func main() {
    utc := time.Now().UTC().Format("15:04")
    hun := timeIn("Hungary").Format("15:04")
    eg := timeIn("Egypt").Format("15:04")
    fmt.Println(utc, hun, eg)
}