kek@donald:~$ uptime 08:17:33 up 293 days, 14:21, 1 user, load average: 0.00, 0.00, 0.00
AFAIK there is no command in Windows to quickly see the uptime. However, there are several commands to get the last boot time, although you’ll have to do a quick calculation if you need the uptime in days. The easiest/fastest method is to use net stats.
net stats srv
C:\Users\kek>net stats srv Server Statistics for \\hostname Statistics since 09.11.2017 00.02.28 # last boot/uptime Sessions accepted 1 Sessions timed-out 0 Sessions errored-out 0 Kilobytes sent 1649 Kilobytes received 1181193 Mean response time (msec) 0 System errors 0 Permission violations 0 Password violations 0 Files accessed 329 Communication devices accessed 0 Print jobs spooled 0 Times buffers exhausted Big buffers 0 Request buffers 0 The command completed successfully.