字符串。拆分行为很奇怪

I am doing a simple strings.Split on a date.

The format is 2015-10-04

month := strings.Split(date, "-")

output is [2015 10 03].

If I do month[0] it returns 2015 but when I do month[1], it returns

panic: runtime error: index out of range

Though it clearly isn't. Am I using it wrong? Any idea what is going on?

Here's a complete working example:

package main

import "strings"

func main() {
    date := "2015-01-02"
    month := strings.Split(date, "-")
    println(month[0])
    println(month[1])
    println(month[2])
}

Output:

2015
01
02

Playground

Perhaps you're not using the correct "dash" character? There are lots:

+-------+--------+----------+
| glyph |       codes       |
+-------+--------+----------+
| -     | U+002D | -    |
| ֊     | U+058A | ֊  |
| ־     | U+05BE | ־  |
| ᠆     | U+1806 | ᠆  |
| ‐     | U+2010 | ‐  |
| ‑     | U+2011 | ‑  |
| ‒     | U+2012 | ‒  |
| –     | U+2013 | –  |
| —     | U+2014 | —  |
| ―     | U+2015 | ―  |
| ⁻     | U+207B | ⁻  |
| ₋     | U+208B | ₋  |
| −     | U+2212 | −  |
| ﹘     | U+FE58 | ﹘ |
| ﹣     | U+FE63 | ﹣ |
| －     | U+FF0D | － |
+-------+--------+----------+

Here is the code with a different input string, which also throws an index out of bounds exception:

package main

import "strings"

func main() {
    date := "2015‐01‐02" // U+2010 dashes
    month := strings.Split(date, "-")
    println(month[0])
    println(month[1])
    println(month[2])
}

Playground.