Think it's a large date no serif. The small date has the 1999 closer together and between the stairway. The 1 has no serif.
That is small date, the date is tighter and it fits inside the stairway if you extrapolate the stairway downwards. Serif will have underline on the 1.
Fishball: can you upload a photo with 1 with serif? I dont Find the translation word for serif in spanish. And 1 photo is more than 1000 words. Thanks in advance.
Fishball is correct this is a 1999 large date no serif (or sometimes referred to as "plain 1"). Either this is a poor picture or it looks like the cats have been playing with it for a while it's in rough shape !
Unfortunately I don't have a picture of one handy and couldn't find anything on Google. Read the Wikipedia article for definition of Serif.