古时

古 = 十 + 口 : Mnemonic symbol: at least on German maps, this character actually resembles a cloister.

Oh no! Gitta Giraffe (gu) found that the golden cross (十) broke off of the cloister (古) in the space station's living room (Ø3)! She skewers a mandarin (口) on top of the cloister so that she can skewer the broken off cross back on to fix it.

时 = 寸 + 日 : Mnemonic symbol: a giant pocket watch.

The sun (日) asks Sherlock Holmes (sh) out for a coffee in the space station's kitchen (Ø2). Looking at his pocket watch (时), Sherlock sees he has time, winks and "thumbs up" (寸).