timesyncd also does this for "large offsets", but what "large" is is neither configurable nor documented, but in the source: /* * Maximum delta in sec

timesyncd also does this for "large offsets", but what "large" is is neither configurable nor documented, but in the source: /* * Maximum delta in seconds which the system clock is gradually adjusted * (slewed) to approach the network time. Deltas larger that this are set by * letting the system time jump. The kernel's limit for adjtime is 0.5s. */ #define NTP_MAX_ADJUST 0.4