ظَرْفُ المَكَانِ و ظَرْفُ الزَََّمَانِ designs to the time and the place of an event (المَفْعُولُ فِيهِ). It is considered an optional part of phrase structure. The word "ظَرْفُ" literary means container, in the Arabic grammar it generally means the container of event. It contains the time الزَََّمَانِ and the place of a certain event المَكَانِ. The tool of questioning about time is "مَتَى" and place is "أَيْنَ".
There is a difference between time and time container. Time container refers to the time of an event but you can use time as a subject or a object (mark the no use of container in other phrase structure). For example: Yesterday was great. الأَمْسُ كَانَ رَائِعََا. In this sentence, yesterday is the subject of the sentence. I came yesterday. جِئْتُ بِالأَمْسِ. In this sentence, yesterday is a time container. (The sentence "I came" still makes sense without yesterday, it just has less precision. It is the same in Arabic, "جِئْتُ" represents a complete sentence.
Time container in Arabic grammar has different groups. There are the inflective words "الظّرفُ المُعْرَبُ" (words that can be used in different positions not only as a time container like the one in the examples). There are the built words (time prepositions) "الظّرفُ المبنيُّ" (these are complex words or simple words that can only refer to time container and cannot be used in other position.
The inflective words, they refer to time in general and can be used as a time container: Second ثانية. I left for a second: غِبْتُ لثَانِيَةٍ Hour ساعة. he will arrive after an hour: سَيَأْتِي بَعْدَ سَاعَةٍ Never أبداً. It will never fly: لَنْ تَطِيرَ أَبَدًا
The built words can't be used in time for general use, it means time container and some time other different meanings. Examples: Since منذُ. I was awake since 6am: كُنْتُ مُسْتَيْقِظًا مُنْذُ السَّادِسَةِ صَبَاحًا. Now الآنَ. I am reading now: أَنَا أَقْرَأُ الآنَ. Until ريثما. I will wait until he comes: سَأَنْتظِر رَيْثَمَا يَأْتِي.