cst-time

提供获取本地主机CST（中国标准时间）的方法和工具。当用户需要获取当前 CST 时间、转换时区或在脚本和应用程序中使用中国标准时间时调用。

## 概述（中文）

提供获取本地主机CST（中国标准时间）的方法和工具。当用户需要获取当前 CST 时间、转换时区或在脚本和应用程序中使用中国标准时间时调用。

## 原文

# CST Time (China Standard Time)

## Overview

This skill provides comprehensive guidance for obtaining and working with China Standard Time (CST), which is UTC+8 and used throughout mainland China. It covers various methods for getting local CST time, time zone conversions, and integration with different programming languages and systems.

## Purpose

CST Time skill helps in:

- Getting current CST time from local system
- Converting between different time zones and CST
- Integrating CST time handling in applications
- Scheduling tasks based on CST
- Displaying and formatting CST time correctly
- Handling daylight saving time considerations (CST doesn't observe DST)

## CST Time Zone Information

**Time Zone Details:**

- **Name**: China Standard Time (CST)
- **UTC Offset**: UTC+8
- **Daylight Saving Time**: Not observed
- **Region**: Mainland China
- **IANA Time Zone ID**: Asia/Shanghai

**Important Notes:**

- CST is 8 hours ahead of Coordinated Universal Time (UTC)
- China does not observe daylight saving time
- CST is used consistently year-round
- Time zone ID for programming: Asia/Shanghai

## Getting CST Time

### 1. Using System Commands

#### Windows (PowerShell)

**Get current system time (assumed to be CST):**

```powershell
Get-Date
```

**Get CST time with explicit time zone:**

```powershell
[System.TimeZoneInfo]::ConvertTimeBySystemTimeZoneId([DateTime]::UtcNow, "China Standard Time")
```

**Format CST time:**

```powershell
Get-Date -Format "yyyy-MM-dd HH:mm:ss"
```

#### Linux/Unix (Bash)

**Get current system time:**

```bash
date
```

**Get CST time explicitly:**

```bash
TZ='Asia/Shanghai' date
```

**Format CST time:**

```bash
date +"%Y-%m-%d %H:%M:%S"
```

#### macOS (Bash)

**Get current system time:**

```bash
date
```

**Get CST time explicitly:**

```bash
TZ='Asia/Shanghai' date
```

### 2. Using Programming Languages

#### Python

**Get current CST time:**

```python
from datetime import datetime
import pytz

# Get current CST time
cst_tz = pytz.timezone('Asia/Shanghai')
cst_time = datetime.now(cst_tz)

print(f"Current CST time: {cst_time}")
print(f"Formatted: {cst_time.strftime('%Y-%m-%d %H:%M:%S')}")
```

**Convert UTC to CST:**

```python
from datetime import datetime
import pytz

# Get UTC time
utc_time = datetime.utcnow().replace(tzinfo=pytz.UTC)

# Convert to CST
cst_time = utc_time.astimezone(pytz.timezone('Asia/Shanghai'))

print(f"UTC: {utc_time}")
print(f"CST: {cst_time}")
```

**Convert any timezone to CST:**

```python
from datetime import datetime
import pytz

# Example: Convert New York time to CST
ny_tz = pytz.timezone('America/New_York')
cst_tz = pytz.timezone('Asia/Shanghai')

ny_time = datetime.now(ny_tz)
cst_time = ny_time.astimezone(cst_tz)

print(f"New York: {ny_time}")
print(f"CST: {cst_time}")
```

#### JavaScript/Node.js

**Get current CST time:**

```javascript
// Using Intl API
const cstTime = new Date().toLocaleString('zh-CN', {
    timeZone: 'Asia/Shanghai',
    hour12: false
});
console.log('Current CST time:', cstTime);

// Using moment-timezone (recommended)
const moment = require('moment-timezone');
const cstTime = moment().tz('Asia/Shanghai').format('YYYY-MM-DD HH:mm:ss');
console.log('Current CST time:', cstTime);
```

**Convert UTC to CST:**

```javascript
const moment = require('moment-timezone');
const utcTime = moment().utc();
const cstTime = utcTime.tz('Asia/Shanghai').format('YYYY-MM-DD HH:mm:ss');
console.log('UTC:', utcTime.format());
console.log('CST:', cstTime);
```

#### Java

**Get current CST time:**

```java
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

// Get current CST time
ZonedDateTime cstTime = ZonedDateTime.now(ZoneId.of("Asia/Shanghai"));
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

System.out.println("Current CST time: " + cstTime.format(formatter));
```

**Convert UTC to CST:**

```java
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.Instant;

// Get UTC time and convert to CST
Instant utcTime = Instant.now();
ZonedDateTime cstTime = utcTime.atZone(ZoneId.of("Asia/Shanghai"));

System.out.println("UTC: " + utcTime);
System.out.println("CST: " + cstTime);
```

#### Go

**Get current CST time:**

```go
package main

import (
    "fmt"
    "time"
)

func main() {
    // Get current CST time
    cstTime := time.Now().In(time.FixedZone("CST", int(8*3600)))
    fmt.Println("Current CST time:", cstTime.Format("2006-01-02 15:04:05"))
}
```

#### C#

**Get current CST time:**

```csharp
using System;

// Get current CST time
TimeZoneInfo cstZone = TimeZoneInfo.FindSystemTimeZoneById("China Standard Time");
DateTime cstTime = TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, cstZone);

Console.WriteLine($"Current CST time: {cstTime:yyyy-MM-dd HH:mm:ss}");
```

### 3. Using Online APIs

**World Time API:**

```bash
curl "http://worldtimeapi.org/api/timezone/Asia/Shanghai"
```

**TimezoneDB API:**

```bash
curl "http://api.timezonedb.com/v1/get-time-zone?key=YOUR_API_KEY&by=zone&zone=Asia/Shanghai"
```

**Google Maps Time Zone API:**

```bash
curl "https://maps.googleapis.com/maps/api/timezone/json?location=39.9042,116.4074&timestamp=1331161200&key=YOUR_API_KEY"
```

## Time Zone Conversions

### 1. UTC to CST

**Formula:**

```
CST = UTC + 8 hours
```

**Python Example:**

```python
from datetime import datetime, timedelta

# UTC to CST
utc_time = datetime.utcnow()
cst_time = utc_time + timedelta(hours=8)

print(f"UTC: {utc_time}")
print(f"CST: {cst_time}")
```

### 2. CST to UTC

**Formula:**

```
UTC = CST - 8 hours
```

**Python Example:**

```python
from datetime import datetime, timedelta

# CST to UTC
cst_time = datetime.now()
utc_time = cst_time - timedelta(hours=8)

print(f"CST: {cst_time}")
print(f"UTC: {utc_time}")
```

### 3. Other Time Zones to CST

**Common conversions:**

| Time Zone        | UTC Offset | CST Offset | Conversion     |
| ---------------- | ---------- | ---------- | -------------- |
| EST (Eastern)    | UTC-5      | +13 hours  | EST + 13 = CST |
| PST (Pacific)    | UTC-8      | +16 hours  | PST + 16 = CST |
| GMT (Greenwich)  | UTC+0      | +8 hours   | GMT + 8 = CST  |
| JST (Japan)      | UTC+9      | -1 hour    | JST - 1 = CST  |
| AEST (Australia) | UTC+10     | -2 hours   | AEST - 2 = CST |

## Formatting CST Time

### Common Format Patterns

**ISO 8601 Format:**

```
2026-02-10T21:30:45+08:00
```

**Standard Format:**

```
2026-02-10 21:30:45
```

**Chinese Format:**

```
2026年2月10日 21:30:45
```

**Time Only:**

```
21:30:45
```

**Date Only:**

```
2026-02-10
```

### Programming Language Formatting

**Python:**

```python
from datetime import datetime

cst_time = datetime.now()
formats = {
    'ISO 8601': cst_time.isoformat(),
    'Standard': cst_time.strftime('%Y-%m-%d %H:%M:%S'),
    'Chinese': cst_time.strftime('%Y年%m月%d日 %H:%M:%S'),
    'Time only': cst_time.strftime('%H:%M:%S'),
    'Date only': cst_time.strftime('%Y-%m-%d')
}

for name, formatted in formats.items():
    print(f"{name}: {formatted}")
```

**JavaScript:**

```javascript
const moment = require('moment-timezone');
const cstTime = moment().tz('Asia/Shanghai');

const formats = {
    'ISO 8601': cstTime.format(),
    'Standard': cstTime.format('YYYY-MM-DD HH:mm:ss'),
    'Chinese': cstTime.format('YYYY年MM月DD日 HH:mm:ss'),
    'Time only': cstTime.format('HH:mm:ss'),
    'Date only': cstTime.format('YYYY-MM-DD')
};

for (const [name, formatted] of Object.entries(formats)) {
    console.log(`${name}: ${formatted}`);
}
```

## Best Practices

### 1. Time Zone Handling

**Recommendations:**

- Always store times in UTC and convert to CST for display
- Use IANA time zone IDs (e.g., Asia/Shanghai) instead of offsets
- Handle daylight saving time properly (CST doesn't observe DST)
- Test time zone conversions thoroughly
- Document time zone assumptions in code

### 2. Time D