At this point, I find myself a bit puzzled with what I'm currently observing. To elaborate, the scenario involves me converting a MongoDate to JSON by utilizing PHP's json_encode function along with MongoDB functionalities. The resulting output contained within my JSON string reads as follows:
"date":{"sec":1344724737,"usec":0}}
While I do comprehend that the sec value pertains to UNIX epoch time (the seconds elapsed since 00:00:00 UTC on January 1st, 1970, if we want to be precise), the purpose and significance of the usec value remain unclear to me. Could it possibly represent an unsigned integer value related to milliseconds? Moreover, should I primarily rely on the sec value for extracting information? Just to put it out there, I intend to transform this data into an NSDate format within an iOS application. Everything seems to work fine in that regard, but delving deeper into the true nature of these values is crucial for ensuring my selection is appropriate (and ultimately granting me some peace of mind once this goes live).