Starting a round on a Garmin Approach watch puts it in a different mode than the watch mode. The hole view (front, middle, back distances) appears on the main screen during a round, but you can still check the time of day without ending the round.

Checking Time During a Round

Approach S1 and S2

From the hole view, hold OK/Menu to see the clock
Hold OK/Menu again to return to hole view

Approach S10, S12, S20, S60 and S62

Form the hole view, press Back to see the clock
Press Back again to return to the hole view

Approach S3, S4, S5, and S6

From the hole view, press on bezel to see the clock
Press to return to the hole view

Approach S40 and S42

From the hole view, press Button to open the golf menu (time of day appears at top of menu)
Press Button again to return to the hole view

Approach X10 and X40

From the hole view, swipe up on touchscreen to see the clock
Swipe down on touchscreen to return to the hole view