@Esteban_Giannini , indeed this is the expected behaviour. You would have to input a 0 value instead of leaving it blank.
@Emily_Roman , perhaps you could raise this to the product team; whether a blank field could instead be considered as 0, or so we can better understand their reasons for this behaviour.
Hi @Richard_Uruchurtu , hopefully this is coming in the near future 
Hi @Tetsuo_Kawakami , nice hack! Also, I found that if you add a +0 on the end, you will get the result in minutes! And if you divide that by 60 then you will get the value in ‘numeric’ hours, i.e 10h30m will display as 10.5, as per below formula which you can copy paste into your advanced editor:
( [[$ACTUAL_TIME]] + 0 ) / 60
Refer to my post here for the complete workaround on getting dashboards to display in hours/days instead of weeks/days.