Linnworks API请求日期时间格式疑问：是否需构造及后缀含义

Great question—let's unpack this date-time format step by step, since it's a common standard used across many APIs, not just Linnworks.

First off: Yes, this is the ISO 8601 extended format, a widely adopted default for API date-time inputs/outputs because it's unambiguous, machine-readable, and timezone-aware.

Now let's break down the suffix you're confused about (0049771+00:00):

• 0049771: This is the microsecond precision of the timestamp. After the seconds (16:57:07), this represents 0.0049771 seconds (4,977.1 microseconds). Many APIs include this level of precision for accuracy, though some might truncate it to milliseconds (e.g., 004+00:00) if that's sufficient.
• +00:00: This is the timezone offset from UTC. +00:00 means the timestamp is in Coordinated Universal Time (UTC)—the "base" timezone used globally to avoid confusion. If you were working with a timezone like Eastern Standard Time (UTC-5), this would be -05:00; for Beijing time (UTC+8), it would be +08:00.

To clarify your other question: This is not a Unix Time Stamp. Unix timestamps are numerical values representing the number of seconds (or milliseconds) since January 1, 1970 UTC—they look like 1519040227 or 1519040227004, not a structured string like the one Linnworks uses.

If you need to construct this format yourself, most programming languages have built-in tools to generate ISO 8601 strings automatically:

• In Python: Use datetime.datetime.utcnow().isoformat(timespec='microseconds') to get the full precision UTC timestamp.
• In C#: DateTime.UtcNow.ToString("o") outputs the "round-trip" format, which matches exactly what Linnworks expects.
• In JavaScript: new Date().toISOString() will give you a similar format (though it typically uses milliseconds instead of microseconds, which most APIs will accept as valid).

内容的提问来源于stack exchange，提问作者Stuart