[zX41ZdbW]

The first rule of thumb is to never use functions from glibc (gmtime, localtime, mktime, etc) because half of them are non-thread-safe, and another half use a global mutex, and they are unreasonably slow. The second rule of thumb is to never use functions from C++, because iostreams are slow, and a stringstream can lead to a silent data loss if an exception is thrown during memory allocation.

ClickHouse has the "parseDateTimeBestEffort" function: https://clickhouse.com/docs/en/sql-reference/functions/type-... and here is its source code: https://github.com/ClickHouse/ClickHouse/blob/74d8551dadf735...

[bagels]

I came to make the thread safe comment. Got bit by that myself formatting is8601, would get wrong output... Sometimes.

I won't believe anyone who tells me that handling time in c/c++ isn't perilous.