at different time vs at different times

Some examples from the web:

• Yet the GALILEO programme entails the same three phases but at different time periods.
• Overview of collateralisation at different time periods of the Osinek loan
• The problem here is that both of the cities were destroyed at different time periods, at least 300 years apart.
• The main measure of effectiveness was the average IOP at different time points (IOP is measured in mmHg - in a patient with glaucoma, the value is generally higher than 21 mmHg).
• the physical deterioration of the media (all media deteriorate at different time scales)
• Since harvesting takes place at different times in different Member States, the deadlines for declarations by producers should be staggered.
• Different intangible assets may be tested for impairment at different times.
• Different cash-generating units may be tested for impairment at different times.
• Different families took him at different times.
• All 4 victims were Abducted at different Times of day.
• But let's all leave the room at different times.
• They will return like clockwork at different times.
• Please specify if various provisions were enforced at different times.
• Consequently, transactions may be recorded at different times by the transactors involved.
• We can do that separately and at different times.
• The former Eastern bloc countries have joined the European Union at different times.
• The Member States each enjoy heritage days at different times of the year.
• All attacked at different times of the day.
• We go to bed at different times.
• Women leave the workforce at different times.

Some examples from the web:

• Fig. - Surveys in the no. position at different times.
• The deforestation activities are monitored by comparing the images produced by COSMO-SkyMed satellites at different times.
• Vinification Technique: the two grape varieties are vinified separately, since they ripen at different times.
• Senile macular degeneration tends to involve both eyes, albeit at different times.
• The Member States each enjoy heritage days at different times of the year.
• The former Eastern bloc countries have joined the European Union at different times.
• Available Discounts: Various special offers running at different times.
• Sometime it happens, that photographers actions take place at different times.
• In the vineyard Barbera and Pinot Noir grapes ripen at different times.
• Different regions of the world peak in oil production at different times.
• Martynova, written at different times and in absolutely various occasions.
• VINIFICATION: The grapes, harvested at different times, ferment separately and are assembled before ageing.
• Because a lunar calendar is used, Ramadan falls at different times each year.
• Different Traderush promotions are offered at different times, but all offer significant financial advantages to the investor.
• The house was built in various stages of construction and at different times.
• Different scales may be needed at different times.
• Women leave the workforce at different times.
• In national school at different times there were about 100 pupils.
• Singers Alistair Griffin and James Fox were both briefly members of the band at different times.
• But has been used at different times in Europe as well.