⏱ 时间转秒数Convert Time to Seconds
把 HH:MM:SS（或 MM:SS）换成总秒数，小时可以很大，结果精确。本地处理。Convert HH:MM:SS (or MM:SS) to total seconds; hours can be very large and the result is exact. Processed locally.
使用说明与常见问题How-to & FAQ
「时间转秒数」是什么？What is the Convert Time to Seconds tool?
把 HH:MM:SS（或 MM:SS）换成总秒数，小时可以很大，结果精确。本地处理。Convert HH:MM:SS (or MM:SS) to total seconds; hours can be very large and the result is exact. Processed locally.
如何使用「时间转秒数」？How do I use the Convert Time to Seconds tool?
输入 HH:MM:SS 或 MM:SS，下方即显示总秒数。Enter HH:MM:SS or MM:SS to see the total number of seconds.
只输入两段时怎么理解？How are two parts read?
两段按 MM:SS（分:秒）理解，三段按 HH:MM:SS 理解；第一段可以超过 59 或 23。Two parts are read as MM:SS and three parts as HH:MM:SS. The first part may be larger than 59 or 23.
很大的小时数会丢精度吗？Do very large hour values lose precision?
不会，第一段最多 30 位，用大整数精确计算，例如 99999999999999999999:00:00 = 359999999999999999996400 秒。No. The first part can have up to 30 digits and is computed with exact big-integer arithmetic; for example 99999999999999999999:00:00 is 359999999999999999996400 seconds.
和时区有关吗？Do time zones matter?
无关，这里换算的是时长，不读取设备时钟。No. It converts a duration and never reads your device clock.
输入和输出是什么样的？What does the input and output look like?
例如输入 01:01:01，输出为：3661。The input 01:01:01 becomes 3661.
「时间转秒数」免费吗？需要注册吗？Is the Convert Time to Seconds tool free? Do I need an account?
「时间转秒数」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Convert Time to Seconds tool is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.