Difficulty and observed hash rate answer different questions
Difficulty is part of the network's proof-of-work target system. This screen reads the provider's difficulty field from returned blocks. Its displayed hash-rate figure uses the common approximation difficulty × 2^32 / 600 hashes per second, converted to exahashes per second.
The 600-second denominator is the target block interval. Consequently, this is a difficulty-implied rate, not a direct measurement of machines currently mining. Bitcoin Core's network-hash-rate RPC instead estimates hash power from a chosen set of recent blocks. The distinction prevents a target-based calculation from being presented as observed hardware activity.
The next boundary is a block height
Bitcoin's mainnet difficulty periods span 2,016 blocks. The monitor calculates the next adjustment-height boundary from the latest returned height, along with progress through the present epoch. These are height calculations; no calendar deadline is inferred from a handful of irregular block timestamps.
Header timestamps are displayed for context and may not precisely describe when a provider observed each block. An unexpectedly old tip produces a notice. Recent blocks can also be reorganized, so the table should be understood as the provider's returned chain view at request time.