In which case it's useful or needed to timestamp log or debug messages with time since the last reload("service timestamps log uptime")? Is anyone using this in practice?

I use 'service timestamps log datetime localtime' on all my stuffs.

_________________
"A problem well stated is a problem half solved". (Charles Kettering)

Same here, always on

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Networking is much like making love to a beautiful woman
Slide your equipment in to the rack, Stick your plug in the socket, and if you have done it right at the end everyone is happy

we add the msec option in the logging, for more accurate event timing

service timestamps log datetime msec localtime

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"If you're good at anticipating the human mind. It leaves nothing to chance."
-Jigsaw

I always use datetime and msec for more accurate timing. If you use uptime, you have to do math which wastes time in my opinion.

Not to mention when days or weeks have elapsed:

18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.142.1 not on common subne
t for Vlan14
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.139.1 not on common subne
t for Vlan11
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.141.1 not on common subne
t for Vlan13
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.139.1 not on common subne
t for Vlan11
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.141.1 not on common subne
t for Vlan13
Feb 3 14:08:40: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastE
thernet0/4 (10), with SWITCH2 FastEthernet0/5 (2).
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.139.1 not on common subne
t for Vlan11
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.142.1 not on common subne
t for Vlan14
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.138.1 not on common subne
t for Vlan10
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.139.1 not on common subne
t for Vlan11
18w5d: IP-EIGRP(Default-IP-Routing-Table:150): Neighbor 10.6.141.1 not on common subne

How the hell do you know at what time an event has ocurred?

At a previous job we had a customer who had the uptime stamps on their gear... And there was a specific reason why they could not use the datetime stamps... But I'll be damned if I remember what that was.

uptime sucks. I avoid it.

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blog.brokennetwork.ca

show ver
tells you time singe last reboot, little math and your in.

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"If you're good at anticipating the human mind. It leaves nothing to chance."
-Jigsaw

Yes, but if you rest "18w5d" to the "show ver" uptime, doesn't tell you an specific hour like 13:51:24, and this specific hour is always important.