On 18/12/2019 15:12, Mark C. Allman wrote:
>
> The month value range is 0 to 11, not 1 to 12. You're calculating
> 12/30/2019 at 23:59:59 to 01/01/2020 at 00:00:00, or 86401 seconds.
>
This is in accord with 'man mktime' but it's certainly a trap for the
unwary. Calendar days are treated normally, but not months. I wonder
how many space probes have strayed or contracts misfired...