On 4 servers with real players, out of 5 Steam servers that run it now, fakes and empty ones included. Checked 03:56 UTC.
80.87.102.104:1047832/64Real players189.74.125.116:4009831/64Real players87.252.237.162:5001327/64Real players89.125.55.16:5001527/64Real playerszm_420_office_p is a zombie map for Zombie Mod servers. It is not one of the maps that come with the game, so servers send it to players from the Workshop when they join.
Over the last 30 days zm_420_office_p was the #133 map on CS2 community servers, with 39 real players on it at any moment on average - 0% of everyone playing. It ran on about 2 servers with real players at a time. Right now 117 people play it on 4 servers, most of them on servers in Russia and Belarus. It is busiest on Sunday around 09:00 UTC and quietest on Monday around 08:00 UTC.
Right now 117, on 4 servers from the Steam server list. Over the last 30 days it had 39 real players on average at any moment. Fake servers and bots are not counted, and Valve matchmaking is not in the list.
On Sunday around 09:00 UTC. The grid above shows every hour of the week in your own time zone.
The busiest right now: [CS2] Zombie Fun Server [ZM] !shop,!zprops,!lm [Unlim Ammo] (32 players), [CS2] Zombie Fun Server [ZM] !shop,!zprops,!lm [Unlim Ammo] (31 players), [CS2] Zombie Fun Server [ZM] !shop,!zprops,!lm [Unlim Ammo] (27 players). The full list is under "Servers running it now", and every server has its own page with its history.
de_mirage43,247 players on average
de_dust217,893 players on average
sandstone_fb14,441 players on average
de_mirage_fps6,334 players on average
awp_lego_25,414 players on average
awp_lego_2_fb4,840 players on average
de_mirage_christmas2,842 players on average
<null>1,271 players on average
bhop_emevaelx31,054 players on average
duels_mirage_1x11,011 players on average
de_inferno903 players on average
de_nuke774 players on average