When working with UTC time formats that need conversion to local time (e.g., UTC+8), here’s a breakdown of the process for the input format yyyy-MM-ddTHH:mm:ss.SSSZ:

• yyyy: 4-digit year
• MM: 2-digit month (01-12)
• dd: 2-digit day (01-31)
• T: Date/time separator
• HH: 24-hour format hour (00-23)
• mm: Minutes (00-59)
• ss: Seconds (00-59)
• SSS: Milliseconds (3 digits)
• Z: Timezone offset (e.g., +0100 for UTC+1)

Example Conversion:
Input: 2018-01-01T12:00:00.000+0100 (UTC+1)
Local Output (UTC+8): 2018-01-01 19:00:00.000 (+7 hours)

Implementation using Carbon:

<?php

use Carbon\Carbon;

// Input time with timezone offset
$input = '2018-01-01T12:00:00.000+0100';

// Parse UTC time with offset
$carbon = Carbon::parse($input);

// Convert to China Standard Time (UTC+8)
$carbon->setTimezone('Asia/Shanghai');  // or 'PRC'

// Output with milliseconds (Y-m-d H:i:s.u)
echo $carbon->format('Y-m-d H:i:s.u');  // 2018-01-01 19:00:00.000

Key Notes:

1. Use Carbon::parse() for ISO 8601 formatted strings
2. Prefer Asia/Shanghai over PRC for clearer timezone identification
3. Include .u in format for milliseconds display
4. Works for any timezone offset in the input (e.g., +0530, -0500)

For non-PHP implementations, similar logic applies using native datetime libraries with timezone support.