三年有三天
[sān nián yŏu sān tiān]
'三年有三天' (sān nián yǒu sān tiān) literally translate into 'there are three days in three years'. In a metaphorical manner, it might express something extremely precious only occurs occasionally, like there are only three significant moments out of thousands of days spanning across three years, or it could refer to someone recalling those particularly meaningful days.